saqarTvelos teqnikuri universiteti beJan kotia eleqtronebis da ...

saqarTvelos teqnikuri universiteti beJan kotia eleqtronebis da ... saqarTvelos teqnikuri universiteti beJan kotia eleqtronebis da ...

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saqarTvelos teqnikuri universitetixelnaweris uflebiTbeJan kotiaeleqtronebis da polaronebis Zvradobis kvanturiTeoriis zogierTi sakiTxi naxevargamtarebsa da ionurkristalebSidoqtoris akademiuri xarisxis mosapovebladwardgenili disertaciisavtoreferatiTbilisi2010 weli1

<strong>saqarTvelos</strong> <strong>teqnikuri</strong> <strong>universiteti</strong>xelnaweris uflebiT<strong>beJan</strong> <strong>kotia</strong><strong>eleqtronebis</strong> <strong>da</strong> polaronebis Zvradobis kvanturiTeoriis zogierTi sakiTxi naxevargamtarebsa <strong>da</strong> ionurkristalebSidoqtoris akademiuri xarisxis mosapovebladwardgenili disertaciisavtoreferatiTbilisi2010 weli1


samuSao Sesrulebulia <strong>saqarTvelos</strong> teqnikur <strong>universiteti</strong>sinformatikisa <strong>da</strong> marTvis sistemebis fakultetisfizikisdepartamentismyari sxeulebis fizikis mimarTulebaze.samecniero xelmZRvaneli: -----------------------------------------------------recezentebi: -----------------------------------------------------------------------------------------------------------------------------------------------------<strong>da</strong>cva Sedgeba ------------ wlis `_____~ --------------------------- saaTze<strong>saqarTvelos</strong> <strong>teqnikuri</strong> <strong>universiteti</strong>s informatikisa <strong>da</strong> marTvissistemebis fakultetis sadisertacio sabWos kolegiissxdomaze, korpusi-------------, auditoria-----------------misamarTi: Tbilisi 0175, kostavas 77disertaciis gacnoba SeiZleba stu-s biblioTekaSi,xolo avtoreferatisa stu-s vebgverdzesadisertacio sabWos mdivani ---------------------------------2


naSromis zogadi <strong>da</strong>xasiaTebaSesavali kristalebSi eleqtronuli ga<strong>da</strong>tanis movlenebis zonuriTeoria principSi <strong>da</strong>fuZnebulia sam ZiriTad koncefciaze: 1) denisga<strong>da</strong>mtanebi warmoadgenen kvazi nawilakebs gansazRvruli kvaziimpulsiT<strong>da</strong> dispersiis kanoniT. 2) denis ga<strong>da</strong>mtanTa eleqtrogamtaroba<strong>da</strong> Zvradoba ganisazRvreba maTi gabneviT kristalis idealuri mesrisstruqturis dinamiur <strong>da</strong> statikur <strong>da</strong>maxinjebebze (defeqtebze). 3) denisga<strong>da</strong>mtanis Tavisufali ganarbenis sigrZe warmoadgens sasrul sidides<strong>da</strong> is bevrad aRemateba Sesabamisad kvazi nawilakis de-broilistalRis sigrZes. am pirobebis gaTvaliswinebiT denis ga<strong>da</strong>mtanTa gabnevaSeiZleba CaiTvalos rogorc “iSviaTi”. am debulebebi<strong>da</strong>n gamomdinare,denis ga<strong>da</strong>mtanTa yofaqceva kristalSi aRiwereba albaTuri ganawilebisfunqciiT kvazi impulsebis mixedviT, romelic ganisazRvreba,rogorc bolcman-bloxis kinetikuri gantolebis amoxsna. ga<strong>da</strong>tanis kinetikuri(meqanikuri) koeficientebis (Zvradoba, eleqtrogamtaroba) gamosaTvleladgamoiyeneba denis ga<strong>da</strong>mtanebis arawonasworuli ganawilebisfunqciisTvis kinetikuri gantoleba–bolcmanis gantoleba–romelic iTvaliswinebs denis (muxtis) matarebelTa urTierTqmedebas(gabnevas) kristaluri mesris rxevebze.ukanasknel wlebSi, eleqtronuli ga<strong>da</strong>tanis movlenebis gamokvlevebSimyari sxeulebis fizikaSi, Zalian farTo gamoyeneba hpova ufrozogadma midgomam, romelic <strong>da</strong>fuZnebulia kubos wrfivi reaqciisTeoriaze. am TeoriaSi-romelsac ga<strong>da</strong>mwyveti mniSvneloba aqvs wrfivarawonasworul TermodinamikaSi–ga<strong>da</strong>tanis kinetikuri (meqanikuri)koeficientebi bunebrivad gamoisaxebian (aRiwerebian) droiTi korelaciurifunqciebiT. isini asaxaven sistemis reaqcias hamiltonianisSeSfoTebisas, romlis tipiur magaliTs warmoadgens eleqtrogamtaroba.amrigad, aRniSnuli<strong>da</strong>n gamomdinare naTelia, rom rogorc samecniero,aseve akademiuri TvalsazrisiT did interess warmoadgens eleqtronuli<strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis koreqtuli kvanturi3


Teoriis ageba <strong>da</strong> ga<strong>da</strong>tanis meqanikuri koeficientebis gamoTvlanaxevargamtarebsa <strong>da</strong> ionur kristalebSi <strong>da</strong>fuZnebuli kubos wrfivireaqciis Teoriaze.Temis aqtualoba Tanamedrove pirobebSi farTod gamokvlevissagans warmoadgens eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebisSeswavlis sakiTxi myari sxeulebisa <strong>da</strong> kondensirebul garemoTafizikaSi. ukanasknel wlebSi, rTuli molekuluri aRnagobis mqonenivTierebaTa Seqmnis tendencia <strong>da</strong> maTi eleqtronuli <strong>da</strong> polaronuliTvisebebis Seswavla stimuls aZlev<strong>da</strong> mravali Teoriuli gamokvlevebisSesrulebas avtolokalizebuli (polaronuli) mdgomareobebisaRsawerad dinamiurad mouwesrigebel sistemebSi. polaronis koncefcias,romelic warmoadgens martiv magaliTs arawrfivi kvazinawilakisa, Zalian didi mniSvneloba <strong>da</strong> gamoyeneba aqvs myari sxeulebis(kondensirebul garemoTa) fizikaSi, <strong>da</strong> kerZod igi mWidrod aris<strong>da</strong>kavSirebuli kvanturi dinamiuri sistemebis Teoriis funadementurproblemebTan <strong>da</strong> velis kvanturi Teoriis sakiTxebTan. eleqtronuli<strong>da</strong> polaronuli movlenebis ganxilvisa <strong>da</strong> Seswavlisas myar sxeulebSi,Teoriuli gamokvlevebis Zalian didi raodenoba samecnieroliteraturaSi miZRvnili aris <strong>eleqtronebis</strong>a <strong>da</strong> polaronebis eleqtrogamtarobisa<strong>da</strong> Zvradobis gamoTvlaze naxevargamtarebsa <strong>da</strong> ionurkristalebSi. es gamokvlevebi <strong>da</strong>fuZnebuli aris sxva<strong>da</strong>sxva TeoriulmeTodebze–grinis funqciis teqnikaze, bolcmanis kinetikuri gantolebisSeswavlaze, TviTSeTanxmebul meTodebze <strong>da</strong> sxva. Sedegebi miRebulisxva<strong>da</strong>sxva meTodebis gamoyenebiT <strong>da</strong> Sesabamisad sxva<strong>da</strong>sxvamiaxloebebze <strong>da</strong>yrdnobiT, Zireulad gansxvavdeba erTmaneTisagan. miuxe<strong>da</strong>vadimisa, rom <strong>eleqtronebis</strong> <strong>da</strong> polaronebis eleqtrogamtarobisa<strong>da</strong> Zvradobis gamoTvla warmoadgens erT-erT uZveles problemas myarisxeulebis fizikaSi, is mainc rCeba erT-erT urTules <strong>da</strong> Znel amocanadTeoriulad amoxsnis TvalsazrisiT.4


amgvarad, Tanamedrove pirobebSi kvlav aqtualurs warmoadgenssakiTxi <strong>eleqtronebis</strong> <strong>da</strong> polaronebis eleqtrogamtarobis <strong>da</strong> Zvradobiskoreqtuli gamoTvlisa naxevargamtarebsa <strong>da</strong> ionur kristalebSi.myari sxeulebis fizikisa <strong>da</strong> arawonasworuli statistikuri meqanikismravali amocanis ganxilvisas Seiswavleba mcire dinamiuri qvesistemisevolucia droSi, romelic imyofeba kontaqtSi didi Tavisuflebisricxvis mqone, Termodinamikur wonasworobaSi myof sistemasTan–TermostatTan.eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis gamokvlevebisasmyar sxeulebSi kubos wrfivi gamoZaxilis Teoriaze <strong>da</strong>yrdnobiT,ZiriTad amocanas warmoadgens zusti, ganzogadoebuli kvanturi evoluciuri(kinetikuri) gantolebebis miReba drois ormomentiani wonasworulikorelaciuri funqciebisTvis kvazinawilakebis aRmweri Sesabamisidinamiuri sidideebisTvis, rodesac xdeba am ukanasknelTaurTierTqmedeba (gabneva) kristaluri mesris rxevebze (fononebze), <strong>da</strong>rodesac fononuri (bozonuri) veli ganixileba rogorc Termostati.samecniero literaturaSi, aseTi saxis gantolebebis misaRebad,rogorc wesi, gamoiyeneba aprioruli hipoTeza–sawyisi korelaciebisSesustebis principi, an msgavsi debulebebi–mag. SemTxveviTi fazebis miaxloeba(Sfm)–rodesac drois sawyisi momentisaTvis mTeli sistemis(qvesistema plus Termostati) statistikuri operatori moicema faqtorizebulisaxiT (mTeli sistemis statistikuri operatori ganixilebarogorc qvesistemisa <strong>da</strong> Termostatis statistikur operatorTa pir<strong>da</strong>pirinamravli). naTelia, rom aseTi <strong>da</strong>Svebebis Sedegad miRebuli ganzogadoebuli,kvanturi evoluciuri gantolebebi wonasworuli korelaciurifunqciebisTvis ar aris zusti.amrigad, eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebiskoreqtuli kvanturi Teoriis asagebad <strong>da</strong> meqanikuri koeficientebis(mag. Zvradoba, eleqtrogamtaroba) gamosaTvlelad naxevargamtarebsa<strong>da</strong> ionur kristalebSi <strong>da</strong> agreTve eleqtron-fononuri sistemis kinetikissakiTxebis gamosakvlevad kubos wrfivi reaqciis Teoriis CarCo-5


ebSi, aqtualurs warmoadgens amocana kvazinawilakebis dinamiuri sidideebisTvisdrois ormomentiani wonasworuli korelaciuri funqciebisTviszusti, ganzogadoebuli, kvanturi evoluciuri gantolebebismiReba–sawyisi korelaciebis Sesustebis principisa <strong>da</strong> Sfm-is gamoyenebisgareSe.samuSaos mizani <strong>da</strong> amocanebi. sadisertacio naSromis mizanswarmoadgens: myari sxeulebis fizikis zogierTi kvanturi dinamiurisistemisTvis, romelic urTierTqmedebs fononur (bozonur) velTan(eleqtron-fononuri sistema, frolixis polaronis modeli, akustikuripolaronis modeli susti eleqtron-fononuri urTierTqmedebisSemTxvevaSi, polaronis feinmanis ganzogadoebuli modeli (fgm)),mowesrigebul operatorTa formalizmsa <strong>da</strong> T-namravlTa teqnikaze<strong>da</strong>yrdnobiT, agreTve liuvilis superoperatoruli formalizmisa <strong>da</strong>proeqciuli operatoris meTodis gamoyenebiT_zusti, ganzogadoebulikvanturi evoluciuri (kinetikuri) gantolebebis miReba <strong>da</strong> gamokvlevadrois ormomentiani wonasworuli korelaciuri funqciebisTvis Sfm-isgamoyenebis gareSe.− Aam modelebze <strong>da</strong>yrdnobiT, <strong>da</strong> am gantolebaTa gamoyenebiT,Tanmimdevruli, srulyofili eleqtronuli <strong>da</strong> polaronuli gamtarobisa<strong>da</strong> <strong>da</strong>baltemperaturuli dreifuli Zvradobis kvanturi Teoriisageba naxevargamtarebsa <strong>da</strong> ionur kristalebSi <strong>da</strong>fuZnebuli kuboswrfivi gamoZaxilisa <strong>da</strong> SeSfoTebis Teoriaze. ga<strong>da</strong>tanis meqanikurikoeficientebis (eleqtrogamtaroba, Zvradoba) gamoTvla kvanturi dinamiurisistemebis zemoTmiTiTebuli modelebisTvis.sadisertacio naSromis ZiriTadi Sedegebi <strong>da</strong> mecnieruli siaxlewarmodgenil sadisertacio naSromSi ga<strong>da</strong>wyvetilia Semdegi amocanebi:− mowesrigebul operatorTa formalizmisa <strong>da</strong> T-namravlTa teqnikis<strong>da</strong>xmarebiT, sawyisi korelaciebis Sesustebis principisa <strong>da</strong> Sfm-isgamoyenebis gareSe, gamoyvanilia <strong>da</strong> gamokvleulia axali, zusti, ganzogadoebulikvanturi evoluciuri (kinetikuri) gantolebebi gamoricxulibozonuri (fononuri) amplitudebiT drois ormomentiani wona-6


sworuli korelaciuri <strong>da</strong> grinis funqciebisTvis dinamiuri qvesistemisTvis,romelic urTierTqmedebs bozonur TermostatTan. miRebuliaagreTve axali, zusti kvanturi kinetikuri gantolebebi korelaciurifunqciebisTvis_liuvilis superoperatoruli formalizmisa <strong>da</strong> proeqciulioperatoris meTodis <strong>da</strong>xmarebiT.− dinamiuri qvesistemis bozonur (fononur) TermostatTan urTierTqmedebishamiltonianis mixedviT, SeSfoTebis Teoriis meore miaxloebaSimiRebulia axali, ganzogadoebuli kvanturi kinetikuri gantolebebigamoricxuli bozonuri amplitudebiT, qvesistemis droisormomentiani wonasworuli korelaciuri funqciebisTvis–rogorc markoviseuli,ise aramarkoviseuli formiT–romelTa <strong>da</strong>jaxebiTi integralebiSeicaven cxa<strong>da</strong>d gamoyofil sawyisi korelaciebis evoluciurwevrebs.− kubos wrfivi reaqciisa <strong>da</strong> SeSfoTebis Teoriis farglebSi,naxevargamtarebisa <strong>da</strong> ionuri kristalebisTvis agebulia eleqtronuli<strong>da</strong> polaronuli <strong>da</strong>balsixSiruli gamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturulidreifuli Zvradobis Tanmimdevruli, koreqtuli kvanturiTeoria, <strong>da</strong>fuZnebuli_kvanturi disipaciuri sistemebis zemoTmiTiTebulimodelebisTvis_ganzogadoebul kvantur kinetikur gantolebebzekorelaciuri funqciebisTvis “deni-denze” eleqtronisa <strong>da</strong> polaronisTvis,romlebic urTierTqmedeben fononebTan Sfm-is gamoyenebisgareSe.− miRebulia <strong>da</strong> gamokvleulia analizuri gamosaxulebebi eleqtronisa<strong>da</strong> polaronis relaqsaciuri maxasiaTeblebisTvis (impulsisrelaqsaciis sixSire <strong>da</strong> sxv.); gamoTvlilia wonasworuli korelaciurifunqciebis–“deni-denze”–milevis dekrementebi <strong>da</strong> oscilirebadifaqtorebi. napovnia eleqtrogamtarobis tenzoris (disipaciuri nawilis)analizuri saxe eleqtron-fononuri sistemisTvis kristalis<strong>da</strong>bali temperaturebisa <strong>da</strong> <strong>da</strong>balsixSiruli gareSe eleqtruli velebisSemTxvevaSi <strong>da</strong> gamoTvlilia ga<strong>da</strong>tanis meqanikuri koeficientebi(Zvradoba, eleqtrogamtaroba) kvanturi disipaciuri sistemebis aR-7


3niSnul modelTaTvis; napovnia “2K BΤ-problemis” nawilobrivi ga<strong>da</strong>-hω wyveta frolixis polaronis <strong>da</strong>baltemperaturuli Zvradobis Teoria-Si.− miRebulia temperaturuli Sesworebebi eleqtronisa <strong>da</strong> polaronisdreiful Zvradobebze, romlebic ganpirobebulia sawyisi korelaciebisevoluciuri wevrebis arsebobiT kvantur kinetikur gantolebebSiwonasworuli korelaciuri funqciebisTvis “siCqare-siCqareze”(“impulsi-impulsze”) eleqtronisa <strong>da</strong> polaronisTvis. <strong>da</strong>dgenilia, romes Sesworebebi warmoadgenen mcire sidideebs Sesrulebuli miaxloebebisa<strong>da</strong> ganxiluli Teoriis farglebSi.sadisertacio naSromis praqtikuli mniSvnelobanaSromSi <strong>da</strong>smuli amocanebis ga<strong>da</strong>wyvetam moiTxova arawonasworulistatistikuri meqanikis zogierTi meTodis Semdgomi ganvi-Tareba. sadisertacio naSromSi miRebuli ZiriTadi Teoriuli Sedegebispraqtikuli mniSvneloba (Rirebuleba) ganisazRvreba imiT, rommiRebuli zusti, ganzogadoebuli kvanturi evoluciuri gantolebebiwonasworuli korelaciuri funqciebisTvis SesaZlebelia gamoyenebuliiqnas ga<strong>da</strong>tanis movlenebis gansaxilvelad <strong>da</strong> gamosakvlevad_kuboswrfivi reaqciis Teoriis farglebSi, sawyisi korelaciebis Sesustebisprincipisa <strong>da</strong> Sfm-is <strong>da</strong>Svebebis gareSe_myari sxeulebis <strong>da</strong> kondensirebulgaremoTa fizikis dinamiur qvesistemaTa sxva modelTaTvis(kvanturi disipaciuri sistemebisTvis), romlebic urTierTqmedebenbozonur velTan (TermostatTan). (mag. brounis kvanturi nawilakismoZraobis Sesaswavlad, romelic ganixileba rogorc wrfivi, milevadiharmoniuli oscilatori, <strong>da</strong> romlis dinamika aRiwereba kaldeiralegetismikroskopuli modeluri hamiltonianiT).naSromSi ganviTarebuli formalizmi, meTodebi <strong>da</strong> miRebuli kinetikurigantolebebi martivad SesaZlebelia ganvrcobil iqnas kinetikurimovlenebis Sesaswavlad <strong>da</strong> ga<strong>da</strong>tanis meqanikuri koeficientebis(mag. Zvradoba, eleqtrogamtaroba) gamosaTvlelad: <strong>eleqtronebis</strong> urTi-08


erTqmedebisas (gabnevisas) arapolarul optikur fononebze, piezoeleqtrulfononebze, agreTve sxva didi radiusis mqone polaronTa modelTaTvis(mag. akustikuri polaronis modelisTvis-eleqtronis fononebTanZlieri urTierTqmedebis SemTxvevaSi). gamoyvanili ganzogadoebulikvanturi kinetikuri gantolebebi korelaciuri funqciebisTvis kvanturidinamiuri qvesistemisTvis, romelic urTierTqmedebs fononurvelTan, SesaZlebelia gamoyenebul iqnas normaluri (arazegamtari)metalebis eleqtrowinaRobis gamosaTvlelad <strong>eleqtronebis</strong> gabnevisasakustikur fononebze. naSromSi warmodgenili formalizmis <strong>da</strong>xmarebiTSesaZlebelia temperaturuli Sesworebebis povna metalTa eleqtrowinaRobisTvis(Sesworebebi blox_grunaizenis formulaSi), romlebicagreTve ganpirobebulia <strong>eleqtronebis</strong> fononebTan urTierTqmedebisassawyisi korelaciebis gaTvaliswinebiT.<strong>da</strong>sacavad gamotanilia Semdegi debulebebi:1. osakas Sedegis ganzogadoeba <strong>da</strong>balsixSiruli kuTri eleqtroga-3mtarobisTvis <strong>da</strong> “2K BΤ-problemis” nawilobrivi ga<strong>da</strong>wyveta frolixishω 0polaronis (eleqtronis) <strong>da</strong>baltemperaturuli Zvradobis TeoriaSi.2. eleqtronis <strong>da</strong>baltemperaturuli statikuri Zvradobis gansxvavebuli(2-jer naklebi) mniSvneloba `bolcmaniseul~ ZvradobasTanSe<strong>da</strong>rebiT akustikuri polaronis modelSi susti eleqtron-fononuriurTierTqmedebis SemTxvevaSi.3. Zlieri eleqtron_fononuri urTierqmedebis SemTxvevaSi <strong>da</strong>baltemperaturuliZvradobis gansxvavebuli yofaqceva eleqtron-fononuribmis mudmivas rigis mixedviT polaronis fgm_Si, pekarismodelTan Se<strong>da</strong>rebiT.4. mcire sididis temperaturuli Sesworebebis arseboba eleqtronis <strong>da</strong>polaronis <strong>da</strong>baltemperaturul Zvradobebze ganxilul modelebSi.naSromis aprobacia disertaciis ZiriTadi Sinaarsi moxsenebuliiyo informatikisa <strong>da</strong> marTvis sistemebis fakultetis fizikis departa-9


mentisa <strong>da</strong> myari sxeulebis fizikis kolegiis samecniero seminarebissxdomebze.disertaciis Sinaarsi <strong>da</strong> ZiriTadi Sedegebi wardgenili iyo: 1986w. q.TbilisSi Catarebul 24-e sakavSiro TaTbirze_»24-? ?????? ???? ??????????? ?????? ?????? ??????????», Tbilisi, 1986w; 1991w q. xarkovSi (ukraina)Catarebul sakavSiro konferenciaze «??????????????????? ????????????????????», ???????, 14-17??? 1991?; 1992w. q. puSCinoSi (ruseTi) CatarebulsaerTaSoriso skolaSi_International Workshop `POLARONS and APPLICATIONS~May 23-31, 1992, Pushchino, Russia; 1992w. q. berlinSi (germania) CatarebulsaerTaSoriso konferenciaze `The 18 th IUPAP International Conference onStatistical Physics, Berlin, 2-8 August 1992~; <strong>saqarTvelos</strong> <strong>teqnikuri</strong> <strong>universiteti</strong>sprofesor_maswavlebelTa samecniero_teqnikur konferenciaze,16-19 noemberi, Tbilisi, 1993w; 1993w. q. trondhaimSi (norvegia)Catarebul saerTaSoriso simpoziumze `The Lars Onsager Symposium. CoupledTransport Processes and Phase Transitions~, June 2-4 1993, Trondheim, Norway; 1993w. q.florenciaSi (italia) Catarebul saerTaSoriso konferenciaze `EPS9TRENDS IN PHYSICS~ Firenze, 14-17 September 1993; 1995w. q. qsiamenSi (CineTi)Catarebul saerTaSoriso konferenciaze `The 19 th UPAP InternationalConference on Statisitcal Physics~, Xiamen 31 July-4 August 1995; 1998w. q. parizSi(safrangeTi) Catarebul saerTaSoriso konferenciaze `XXth IUPAPINTERNATIONAL CONFERENCE ON STATISTICAL PHYSICS~, Paris, July 20-24,1998, UNESCO Sorbonne.publikaciebi: disertaciis ZiriTadi Sedegebi gamoqveyenebuliaCvidmet samecniero naSromSi, romelTa <strong>da</strong>saxeleba moyvanilia avtoreferatisbolos.naSromis moculoba <strong>da</strong> struqtura: disertaciis sruli moculobaSeadgens 157 nabeWd gverds; disertacia Sedgeba reziumesagan (or enaze),sarCevisagan, naxazebis nusxisagan, Sesavlisagan, sami Tavisagan,ilustraciis saxiT moyvanili sami naxazisgan, <strong>da</strong>skvnebisa <strong>da</strong> 125<strong>da</strong>saxelebis mqone gamoyenebuli literaturis siisgan, erTi <strong>da</strong>narTisa10


<strong>da</strong> avtoris mier gamoqveynebuli samecniero naSromebisgan, romlebSiacasaxulia disertaciis ZiriTadi Sedegebi.sadisertacio naSromis SinaarsiSesavalSi <strong>da</strong>sabuTebulia Temis aqtualoba, Camoyalibebulia naSromismiznebi <strong>da</strong> amocanebi, <strong>da</strong> gansazRvrulia kvlevis obieqtebi <strong>da</strong>meTodebi.pirveli Tavi ZiriTa<strong>da</strong>d atarebs mimoxilviT xasiaTs$1.1 (1.1.1-1.1.6)_Si moyvanilia modeluri hamiltonianis saxe dinamiurisistemebisa, romlebic urTierTqmedeben bozonur TermostatTan <strong>da</strong> ganxiluliazogierTi aqtualuri magaliTi kvanturi disipaciuri <strong>da</strong> Riaarawonasworuli modeluri sistemebisa Tanamedrove fizikis sxa<strong>da</strong>sxva<strong>da</strong>rgi<strong>da</strong>n, romlebic gaxdnen intensiuri kvlevisa <strong>da</strong> Seswavlis saganiukanaskneli 30-40 wlis ganmavlobaSi. am farTo gamokvlevaTa speqtrimoicav<strong>da</strong> metalTa eleqtrogamtarobisa <strong>da</strong> zegamtarobis Teoriis, metalTaSenadnobebisa <strong>da</strong> ga<strong>da</strong>civebuli `metaluri minebis~ eleqtronuliTeoriis sakiTxebs; susti <strong>da</strong> Zlieri lokalizaciisa <strong>da</strong> Zlier araerTgvarovannivTierebaTa eleqtrogamtarobis Teoriis sakiTxebs mouwesrigebelsistemaTa fizikaSi; lazeruli gamosxivebisa <strong>da</strong> zegamosxivebisTeoriis aspeqtebs kvantur radiofizikaSi; magnituri polaronebis<strong>da</strong> fluqtuonebis (fazonebis) Teoriis sakiTxebs magniturnivTierebebSi (garemoebSi) <strong>da</strong> sxva.$1.2 (1.2.1-1.2.2.)_Si ganxilulia dinamiurad mouwesrigebeli sistemaeleqtron-fononuri sistema <strong>da</strong> eleqtronis urTierTqmedeba akustikur<strong>da</strong> polarul optikur fononebTan; moyvanilia eleqtron-fononuri sistemishamiltonianis zogadi saxe (frolix-pekaris tipis hamiltoniani),eleqtronis akustikur <strong>da</strong> polarul optikuri fononebTan urTierTqmedebishamiltonianTa saxeebi <strong>da</strong> mokled mimoxilulia agreTve deformaciispotencialis meTodi.$1.3 (1.3.1-1.3.3)_Si moyvanilia didi radiusis mqone polaronTa modelebi.ganxilulia polaronis frolixisa <strong>da</strong> pekaris modelebi <strong>da</strong>polaronis feinmanis erToscilatoriani <strong>da</strong> feinmanis ganzogadoebu-11


li modelebi. amave paragrafSi ganxilulia agreTve ukanasknel wlebSiganviTarebuli <strong>da</strong> gamoyenebuli axali midgoma polaronuli sistemebisTermodinamikisa <strong>da</strong> kinetikis sakiTxebis gamokvlevebisas _ mowesrigebulioperatorTa formalizmi, T_namravlTa meTodi <strong>da</strong> fononurioperatorebis gamoricxvis teqnika eleqtron-fononuri sistemis maxasiaTebelifizikuri sidideebis wonasworuli <strong>da</strong> arawonasworulisaSualo mniSvnelobebi<strong>da</strong>n. aRniSnulia zogierT SemTxvevebSi am axalimidgomis upiratesoba, kontinualuri integri-rebis meTodTanSe<strong>da</strong>rebiT, eleqtron-fononuri sistemis kinetikis sakiTxebisSeswavlisas.$ 1.4._Si ganxilulia fizikuri kinetikis zogierTi principuli sakiTxidinamiuri sistemebisa, romlebic urTierTqmedeben fononur(bozonur) velTan. mimoxilulia metad mniSvnelovani <strong>da</strong> principulisakiTxi, K_tipis dinamiur sistemebSi (rogorc klasikuris, aseve kvanturisTvis),evoluciuri (kinetikuri) gantolebebis gamoyvanis drosSemoklebuli aRweris SesaZleblobaze, romelic ar eyrdnoba hipo-Tezas_sawyisi korelaciebis Sesustebisa <strong>da</strong> Sfm-is gamoyenebis Sesaxeb.aRwerilia is ZiriTadi sqemebi <strong>da</strong> meTodebi, romlebsac mivyavarTbolcmanis saxis kinetikuri gantolebisa <strong>da</strong> ZiriTadi kinetikuri gantolebismiRebamde. ganxilulia is ZiriTadi principuli xasiaTissirTuleebi, romlebic warmoiSvebian eleqtron-fononuri sistemisa <strong>da</strong>polaronTa zemoTmoyvanil modelTaTvis dreifuli Zvradobebis gamo-Tvlisas, gamomdinare rogorc bolcmanis kinetikuri gantolebi<strong>da</strong>n <strong>da</strong>kubos wrfivi reaqciis Teorii<strong>da</strong>n, aseve gamtarobis wrfivi <strong>da</strong> arawrfiviTeoriebis zogierTi sxva meTodebis (arawonasworuli simkvrivismatricis meTodi, balansis gantolebis meTodi) gamoyenebisas.meore Tavi sadisertacio naSromSi originaluri xasiaTisaa.am TavSi <strong>da</strong>smulia <strong>da</strong> ga<strong>da</strong>wyvetilia zogadi saxis amocana_dinamiuriqvesistemisTvis, romelic urTierTqmedebs bozonur (fononur)TermostatTan_axali, zusti ganzogadoebuli kvanturi evoluciurigantolebebis miReba drois ormomentiani wonasworuli korelciuri12


<strong>da</strong> grinis funqciebisTvis sawyisi korelaciebis Sesustebis principisa<strong>da</strong> Sfm_is gamoyenebis gareSe.$2.1_Si ganxilulia mowesrigebuli operatorTa formalizmi <strong>da</strong>T_namravlTa meTodi.$2.2_Si am formalizmze <strong>da</strong>yrdnobiT gamoyvanilia axali, zusti,araCaketili ganzogadoebuli kvanturi kinetikuri gantolebebi wonasworulikorelaciuri funqciebisTvis, rogorc markoviseuli, asevearamarkoviseuli saxis, sai<strong>da</strong>nac gamoricxulia bozonuri amplitudebi.miRebuli zusti kvanturi kinetikuri gantolebebis <strong>da</strong>jaxebiTi intgralebiSeicaven <strong>da</strong>matebiT wevrebs, romlebic aRweren sawyisi korelaciebisevolucias droSi, ganpirobebuls qvesistemis urTierTqmedebiTbozonur TermostatTan drois sawyis momentSi. napovniaagreTve msgavsi saxis evoluciuri gantoleba grinis (<strong>da</strong>gvianebuli)funqciisTvis. sadisertacio naSromis <strong>da</strong>narTSi detalurad aris aRwerilibozonuri operatorebis (amplitudebis) gamoricxvis teqnikadrois ormomentiani wonasworuli korelaciuri funqciebis evoluciuri(kinetikuri) gantolebebi<strong>da</strong>n.$2.3_Si ganxilulia markoviseuli miaxloeba qvesistemis dinamikisTvis<strong>da</strong> qvesistemis TermostatTan urTierTqmedebis hamiltonianismixedviT SeSfoTebis Teoriis meore miaxloebaSi gamoyvanilia axali,ganzogadoebili markoviseuli kvanturi kinetikuri gantoleba droisormomentiani wonasworuli korelaciuri funqciisTvis < B sA s( − t)>:13


∂∂tti1BA ( − t) = [ HB ] ⋅A ( −t) − ⎡2( 1 + ( ))×−hh∑∫ dξ⎣N βs s s s s kk 0( , ξ) ⎡ ( ),⎤ ( ) ( β)× e C s − ⋅ C s B A − t + N e ×iω( k) ξ + −iω( k)ξkH0⎣ k s⎦−s k1× C s − ⋅ C s B A − t + d + N ×t+kH01 ⎣ k s⎦−s⎦2h∑∫ ⎣ kk 0( ξ) ⎡ ( ), ⎤ ( ) ⎤ ξ ⎡( 1 ( β))( ), ⎤ ( , ξ) ( ) ( β)× e ⋅ ⎡C s B C s − A − t + N e ×− iω( k) ξ +iω( k)ξ⎣ k s⎦−kH0s khβ+× ⎡⎣C ( s), B ⎤⎦⋅C s,k s−kH ( ) ( ) ⎤ i−ξ A −t − ⎡( 1 + ( ))×0s⎦2 ∑h∫ dθ ⎣N βk( , θ) ⎡ ( ),⎤ ( ) ( β)× e e C s −t−i C s B ⋅ A − t + N e ×− θω( k) iω( k) t +θω( k)kH0⎣ k s⎦−s k( θ ) ⎡ ( ) ⎤ ( )− iω( k)t +× e C s, −− t i ⋅ , ⋅ − ⎤.kH0⎣C s Bk s⎦ A t− s⎦k0(1)sa<strong>da</strong>c H s _qvesistemis hamiltoniania, A s , B s C k (s), C + k (s) –qvesistemisoperatorebia, N k (β)=[e β h ω(k) -1] -1 _warmoadgens bozonebis Sevsebis saSualoricxvs, xolo operatorebi C kH( S,) <strong>da</strong> C kH( S,) _ gansazRvruliatolobebiT:0Z0ZC kH( S,) = e0ZiH 0ZhC ( S)eki− HoZhC kH+ih( S,Z)= e0H0ZC+k( S)ei− HoZhH ;0= Hs+ H∑<strong>da</strong> H Σ - aris bozonuri Termostatis hamiltoniani. analogiurisaxis gantolebebia miRebuli agreTve sxva korelaciuri funqciebisTvis.$2.4_Si ganxilulia <strong>da</strong> ganviTarebulia meore (gansxvavebuli) midgomaigive problemisadmi, romelic eyrdnoba liuvilis superoperatorulformalizmsa <strong>da</strong> proeqciuli operatoris meTods. am formalizmisa<strong>da</strong> meTodis <strong>da</strong>xmarebiT napovnia axali, zusti ganzogadoebulikvanturi evoluciuri (kinetikuri) gantolebebi wonasworuli korelaciurifunqciebisTvis Sfm_is gamoyenebis gareSe. gamoyvanil kinetikurgantolebas < A sB s( − t)>_korelaciuri funqciisTvis aqvs Semdegi saxe:14


∂∂t( ) [ ] ( ) { ( , β )AB − t = i ΡL ΡA B −t −i ΡI t ×s s s s s Q−1( ) ( β) ⎤} ( )× ⎡⎣1 + MQ t IQ t,⎦ MQQLiΡAs Bs− t + dτ×{ LQM ( t τ ) ( t, β) ⎡1 M ( t) ( t,β)× Ρi Q− IQ ⎣ +QIQ⎤⎦×( ) } ( τ ) τ ⎡ ( τ)× M t QLΡA B − − d ⎣ΡLQM t− Q×Q i s s i Q0] ( τ )× LΡA B −i s s.t∫t∫0−1(2)1sa<strong>da</strong>c L = [ KSK HS, ]−_liuvilis superoperatoria, romelic SeesabamebaS–qvesistemis H S –hamiltonians, P-warmoadgens Termostatish(bozonuri velis) mdgomareobebis mixedviT gasaSualebis proeqciuloperators:2P =P <strong>da</strong>Q = 1 − P ; xolo `masuri~ M Q (t) <strong>da</strong> integraluriI ( t,β ) superoperatorebi gansazRvrulia Semdegi tolobebiT:QiLt λH λHM Q( t)= exp[ iQLQt ];Q ( t,β) dλe − e Hinte −QβI =∫miRebuli aramarkoviseuli saxis zusti, ganzogadoebuli (2)_kinetikuri gantolebis <strong>da</strong>jaxebiTi integrali Seicavs wevrebs, romlebicaRweren sawyisi korelaciebis evolucias droSi. (sawyisi korelaciebisevolucia drois mixedviT aRiwereba I ( t,β ) _ integralurisuperoperatoriT <strong>da</strong> es evolucia moicema rogorc markoviseuli, asevearamarkoviseuli formiT).$2.5_Si, iseve rogorc $2.3_Si, ganxilulia markoviseuli miaxloebaqvesistemis dinamikisTvis <strong>da</strong> qvesistemis TermostatTan urTierTqmedebisliuvilianis mixedviT _ SeSfoTebis Teoriis meore miaxloebaSi,proeqciuli operatoris meTodis <strong>da</strong>xmarebiT_napovnia axali,ganzogadoebuli markoviseuli kvanturi kinetikuri gantoleba wonasworulikorelaciuri funqciisTvis < A sB s( − t)>_gamoricxuli bozonuriamplitudebiT:0Q15


nTa modelebSi, polaronis fgm_Si. gamokvleva <strong>da</strong>fuZnebulia kuboswrfivi gamoZaxilisa <strong>da</strong> SeSfoTebis Teoriaze. gamoTvlilia eleqtronuli<strong>da</strong> polaronuli ga<strong>da</strong>tanis meqanikuri koeficientebi(<strong>da</strong>baltemperaturuli Zvradoba, eleqtrogamtaroba) zemoT miTiTebulmodelebSi_korelaciuri funqciebisTvis miRebul ganzogadoebul kvanturkinetikur gantolebebze <strong>da</strong>yrdnobiT.$3.1_Si gamokvleulia eleqtron-fononuri sistema <strong>da</strong> gamoTvliliaeleqtronis <strong>da</strong>baltemperaturuli Zvradoba <strong>da</strong> <strong>da</strong>balsixSirulieleqtogamtaroba susti eleqtron-fononuri urTierTqmedebis SemTxvevaSi(1) <strong>da</strong> (3)_gantolebebze <strong>da</strong>yrdnobiT miRebulia miaxloebiTikinetikuri gantoleba eleqtronis `siCqare_siCqareze~ wonasworulikorelaciuri funqciisTvis. napovnia am bolcmanis tipis gantolebisamonaxsni kristalis <strong>da</strong>bali temperaturebis SemTxvevaSi erTi zonisa<strong>da</strong> relaqsaciis drois miaxloebaSi (rdm) eleqtronisTvis, <strong>da</strong> fononebisdispersiis nebismieri izotropuli kanonis dros. <strong>da</strong>dgenilia,rom eleqtronis (qvesistemis) korelaciuri funqciebi miilevian oscilaciebiTdidi droebis asimptotur areSi, gamoTvlilia korelaciurifunqciebis milevis dekrementi <strong>da</strong> oscilirebadi faqtori. gamoyvaniliazogadi formulebi kuTri eleqtrogamtarobis disipaciuri nawilisTvisizotropul SemTxvevaSi <strong>da</strong> eleqtronis <strong>da</strong>baltemperaturuli,eleqtruli velis ω_sixSireze <strong>da</strong>mokidebuli ZvradobisTvis (acmobility). am formulebs aqvs Semdegi saxe:⎛1⎞th⎜βhω2⎟⎝ ⎠ r⎧ ⎡βh⎤= ∫ Ρ Ρ Ρ Ρ ⎨ ⎢Γ Ρ ×hω⎣ 2 ⎥⎩⎦s 2relRe σµνne d ρs( β, ) Vν ( ) Vµ ( ) cosν( β, )relrel( , )⎫Γ ( , )Γ Ρνβ Ρ ⎡βhrel ⎤ µβ ⎪× + cos Γ ( , Ρ) ,22 ⎢ µβ22⎬rel( , ) ⎣ 2 ⎥relω + ⎡Γ Ρ ⎤ ⎦⎣ ⎦ + ⎡⎣Γ ( , Ρ)⎤νβ ωµβ ⎦ ⎪⎭sa<strong>da</strong>c: µ ( ω)= µ0(ω)− ∆µ( ω)(4)17


µ⎛ 1 ⎞eth⎜βhω⎟⎪⎧rrrelΓ ⎪⎫⎝ 2 ⎠r r r rrelΓ ( , )( , P)Vβ Pµβω)= ∫dPρs(β,P)VV( P)Vµ( P)⎨r +⎬;2 rel2rhω2 rel⎪⎩ ω + [ ΓV( β,P)] ω + [ Γµ( β,P)] ⎪⎭0( 2⎛ 1 ⎞2eth⎜βhω⎟∆ =⎝ 2 ⎠r r r rµ ( ω)∫ dPρS(β,P)VV( P)Vµ( P)×(5)hω⎪⎧rrrelrel2( , )2( , ) ⎪⎫⎡βhrrel ⎤ Γ⎡⎤ Γ⎨sin ( , )2sin ( , )2 ⎬;42⎢[ ( , )] 4 ⎥ ⋅ PVβ P βhrrelµβ−1× ⎢ ΓVβ P ⎥r + Γµ β Pr ( ω


lsis relaqsaiciis sixSire ar aris <strong>da</strong>mokidebuli TviT eleqtronisimpulsze <strong>da</strong> warmoidgineba Semdegi saxiT:~relrel 2~ 2Γz ( γ , Ρ)≡ Γ0 ( γ ) = αω0Ν0( γ ); ( Ρ > 1) (6)3sa<strong>da</strong>c: ω 0 _ fononebis rxevis sixSirea, α_ warmoadgens eleqtron-fononuriurTierTqmedebis (frolixis) bmis mudmivas, <strong>da</strong>N−10( γ ) = [ eγ −1]eleqtronis `siCqare-siCqareze~ korelaciuri funqciisTvis miRebulibolcmanis tipis miaxloebiTi kinetikuri gantoleba amoxsnilia rdm-Sikristalis <strong>da</strong>bali temperaturebis SemTxvevaSi, <strong>da</strong> napovnia eleqtrogamtarobis<strong>da</strong> Zvradobis mniSvnelobebi frolixis polaronis modelSi_racfaqtiurad warmoadgens osakas Sedegis ganzogadoebas (drudesformulas) <strong>da</strong>bal sixSiruli eleqtrogamtarobisTvis <strong>da</strong> <strong>da</strong>baltemperaturuliZvradobisTvis, romlebic Seicaven temperaturul Sesworebebs,ganpirobebuls eleqtronis fononebTan arsebuli sawyisi korelaciebiT:2Re ~ ne 2 ⎛ 1 ~ ⎞⎡( ))2⎛γ⎞⎤Γ0γσ(ω = ~ th⎜γω ⎟ 1 2sin0() ~ ;22⎢ − ⎜ Γ γ ⎟mω2⎥20γω ⎝ ⎠⎣⎝ ⎠⎦ω + Γ0( γ)( α < 1, γ >> 1, ωγ ~ > 1, ω~γ


µ0=emω0Γ−10e( γ ) =mω03e2α2e2 ⎡γ⎤ −1e 1 2 −γ∆µ= sin⎢Γ0( γ ) Γ0( ) ≈;02 ⎥γ αγ e(9)mω⎣ ⎦ mω03( γ >> 1, α < 1).gamoTvlilia agreTve eleqtrogamtaroba <strong>da</strong> eleqtronis Zvradobaeleqtruli velis maRali ω ~ -sixSireebis SemTxvevaSi. am Sem-TxvevaSic temperaturuli Sesworeba eleqtronis Zvradobaze warmoadgensZalian mcire sidides.sadisertacio naSromis am paragrafSi avtoris mier miRebuli3 KSedegi (ix. (9) formula) warmoadgens ` BT2 hωγ;0-problemis~ nawilobrivga<strong>da</strong>wyvetas frolixis polaronis (eleqtronis) <strong>da</strong>baltemperaturuliZvradobis TeoriaSi. Zvradobis miRebuli mniSvneloba 3-jer aRemateba`bolcmaniseul~ <strong>da</strong>baltemperaturul statikur Zvradobas:1 γµ = eB. e ;mω2α( ω = 0, γ >> 1);<strong>da</strong> 1 -mamravliT gansxvavdeba fxip-isa2γ0(feinmani, xelvorsi, idingsi, platcmani) <strong>da</strong> tornberg_feinmanis Sede-e 3 1 γgisgan: µFXIP= µTF=e ; ( ω = 0, γ >> 1);rac Seexeba TviT fxip-isamω2γ2α0<strong>da</strong> tornberg_feinmanis Sedegebis Tanxvedras <strong>da</strong>1 _mamravls, maTi2γwarmoSobis buneba (Rrma mizezi) dRevandel dRemde bolomde <strong>da</strong>dgeniliar aris.$3.3_Si ganxilulia <strong>da</strong> gamokvleulia eleqtronis Zvradobisyofaqceva akustikuri polaronis modelSi susti eleqtron-fononuriurTierTqmdebis dros. am SemTxvevaSi adgili aqvs eleqtronis urTierTqmedebasdispersiis mqone akustikur fononebTan: ω ( k ) = V . k (Vr rs_bgeris siCqarea kristalSi), <strong>da</strong> iseve rogorc polaronis frolixismodelSi, eleqtronis energiisTvis gamtarobis zonaSi gvaqvs dispersiisparaboluri kanoni: T ( P)= P / 2m;(m-eleqtronis efeqturir r2masaa).am paragrafSic miRebuli Sedegebi eleqtrogamtarobisa <strong>da</strong> eleqtroniss20


Zvradobis yofaqcevis Sesaxeb eyrdnoba $3.1_Si gamoyvanil zogadTanafardobebsa <strong>da</strong> formulebs. napovnia eleqtronis `siCqare_siCqareze~_korelaciurifunqciebis milevis dekrementebi (eleqtronis impulsisrelaqsaciis sixSire) <strong>da</strong> oscilirebadi faqtorebi. ganxiluliaeleqtronis aradrekadi gabnevis procesebi akustikur fononebze <strong>da</strong>~<strong>da</strong>dgenilia, rom `mcire~ siCqariT ( P < 1)moZravi eleqtronisTvis, implsisrelaqsaciis sixSire (dro) kristalis Zalian <strong>da</strong>bali temperaturebisdros ar aris <strong>da</strong>mokidebuli TviT eleqtronis impulsismniSvnelobebze <strong>da</strong> warmoidgineba Semdegi saxiT:ΓrelAc( γ ) = τ−1relAcmV( γ ) = sh264α4γ−[ e −1] 1~( Ρ >1;α < 1 ).(10)2~mVssa<strong>da</strong>c: P = P / mV s: <strong>da</strong> γ = : xolo α_eleqtron-fononuri2KT2 2D murTierTqmedebis (bmis) mudmivaa: α = < 1.D_deformaciis pote-38πρhncialis mudmivaa, ρ_kristalis masuri simkvrive. napovnia `siCqaresiCqareze~korelaciuri funqciisTvis miRebuli bolcmanis tipismiaxloebiTi kinetikuri gantolebis amonaxsni rdm-Si kristalis <strong>da</strong>balitemperaturebis dros, <strong>da</strong> gamoTvlilia <strong>da</strong>balsixSiruli kuTrieleqtrogamtaroba <strong>da</strong> eleqtronis Zvradoba am modelSi izotropulSemTxvevaSi <strong>da</strong> erTi zonis miaxloebaSi:BV s2 relne Γ ⎡ ⎤Ac(γ)hγrelReσAc(ω)= cos⎢Γ ( γ)2 2rel2 Ac ⎥m ω +ΓAc( γ)⎣mVs⎦(11)( α < 1; γmV>> 1; ω


∆µAc=m V4γ[ αγe]he1 4γ2e sin 32−2 2s32α; ( α < 1; γ >> 1)naTelia, rom temperaturuli Sesworeba eleqtronis <strong>da</strong>baltemperaturulZvradobaze, romelic ganpirobebulia sawyisi korelaciebisgaTvaliswinebiT, warmoadgens Zalian mcire sidides. miRebuli formulebiwarmoadgenen Tanmimdevrul <strong>da</strong> koreqtul Sedegs eleqtronis<strong>da</strong>baltemperaturuli ZvradobisTvis akustikuri polaronis modelSisusti eleqtron_fononuri bmis SemTxvevaSi.am paragrafSi gamoTvlilia aseve elqtrogamtaroba <strong>da</strong> eleqtronisZvradoba akustikuri polaronis modelSi eleqtruli velismaRali ω_sixSireebis SemTxvevaSi, kristalis rogorc maRali, aseve<strong>da</strong>bali temperaturebis dros, napovnia am sidideebis ω_sixSiresa <strong>da</strong>Τ_temperaturaze <strong>da</strong>mokidebuleba (yofaqceva) am parametrebissxva<strong>da</strong>sxva mniSvnelobebis dros. am SemTxvevaSic temperaturuliSesworeba eleqtronis <strong>da</strong>baltemperaturul Zvradobaze warmoadgensZalian mcire sidides.eleqtronis <strong>da</strong>batemperaturuli Zvradobis gamosaTvlelad akustikuripolaronis modelSi susti eleqtron-fononuri bmis SemTxvevaSi(α> 1, α < 1, ω 0).2 2m Vs 32α0 BAC=xolo, fxip-is Teoriisa (miaxloebisa) <strong>da</strong> balansis gantolebis meTodis(tornberg-feinmanis Teoriis) gamoyenebiT napovni eleqtronis<strong>da</strong>baltemperaturuli statikuri Zvradobis mniSvneloba tolia sidids:µ ~FXIPAC~ TF 3 1 4γhe= µ;~AC= ⋅ e µ = µ , ( γ >> 1, α < 1)2 24γ64αm Vsavtoris mier napovni <strong>da</strong>baltemperaturuli statikuri ZvradobismniSvneloba Sfm_Si (ix. 12 formula). warmoadgens Tanmimdevrul <strong>da</strong>koreqtul Sedegs akustikuri polaronis modelSi. is 2_jer naklebia(13)(14)22


eleqtronis `bolcmaniseul~ <strong>da</strong>baltemperaturul Zvradobaze <strong>da</strong>3 -4γmamravliT gansxvavdeba fxip-isa <strong>da</strong> tornberg-feinmanis Sedegasgan. racSexeba fxip-isa <strong>da</strong> tornberg-feinmanis Sedegebis Tanxvedras <strong>da</strong>3 -4γmamravls_iseve, rogorc polaronis froli-xis modelSi, am modelSicmaTi warmoSobis Rrma mizezi (buneba) jer-jerobiT <strong>da</strong>dgenili ar aris.$3.4_Si ganxilulia polaronis fgm. gamoTvlilia <strong>da</strong> gamokvleuliakontinualuri optikuri polaronis drefuli Zvradoba <strong>da</strong> misiyofaqceva am modelSi <strong>da</strong>bali temperaturebis SemTxvevaSi. gamoyvaniliakvanturi kinetikuri gantolebebi polaronis `impulsi-_impulsze~(`deni_denze~). wonasworuli korelaciuri funqciebisTvis,ganxilulia markoviseuli miaxloeba polaronis dinamikisaTvis <strong>da</strong>didi droebis asimpatotur areSi: t ~ τ >> t = 0max (t s , t Σ ); τ >> β;h = m = ω = 1). (t 0 s-polaronis <strong>da</strong>jaxebaTa maxasiaTebeli droa, t Σ -arisTermostatSi fluqtuaciebis korelaciebis maxasiaTebeli dro), miRebuliamiaxloebiTi gamosaxulebebi korelaciuri funqciebisTvis.gamoyvanilia agreTve kinetikuri gantolebebi korelaciuri funqciebisdiagonaluri matriculi elementebisTvis. napovnia korelaciurifunqciebis milevis dekrementebi (polaronis impulsis relaqsaciissixSire) <strong>da</strong> oscilirebadi faqtorebi.relrel−1<strong>da</strong>bali temperaturebis SemTxvevaSi ( β >> 1,β > εi− εj)-polaronis P P ( t)− korelaciuri funqciebissidide ZiriTa<strong>da</strong>d gansazRvrulia impulsTa im mniSvnelobebiT,romelTaTvisac P r 2


polaronis P r impulsze (`mcire~ siCqariT moZravi polaroni) <strong>da</strong> ganisazRvrebaTanafardobiT:r)GFGF 2Γzrel( β , Ρ)≡ Γ0rel( β ) =3αN0( β ) M f ( 2Mr)2( β >> 1, Ρ / 2M |(16)napovni (<strong>da</strong>balsixSiruli) kuTri eleqtrogamtarobisTvis <strong>da</strong> polaronis<strong>da</strong>baltemperaturuli ZvradobisaTvis gvaqvs Semdegi saxisgamosaxulebebi:12th(βω)GFGF2 −1Γ⎡ ⎤=20rel( β)β GFRe σ ( ω)Ne β Mcos⎢Γ0( β)2 2GFrelω ω + Γ ( β)⎣ 2 ⎥(17)⎦0relGF−1( ω


ga<strong>da</strong>dis polaronis frolixis modelSi, polaronis <strong>da</strong>baltemperaturuliZvradobisTvis gvaqvs:GF 3eβµ0⇒ µ0= e ;1 GF2 −β∆µ⇒ ∆µ= eαβe ;( α < 1, β >> 1)2α3romelic emTxveva <strong>da</strong>baltemperaturuli Zvradobis mniSvnelobaspolaronis frolixis modelSi.2. Zlieri eleqtron-fononuri bmis zRvrul SemTxvevaSi: (α>>1, M GF >>1,M GF →8), rodesac fgm aRadgens pekaris Teorias, polaronis <strong>da</strong>baltemperaturuliZvradobis yofaqceva aRiwereba TanafardobiT:µ3e~ exp( β ) α2;GF13oΠ( >> 1, β >> 1)α (20)sadisertacio naSromSi avtoris mier ganviTarebuli formalizmi<strong>da</strong> meTodebi, miRebuli ganzogadoebuli kvanturi kinetikurigantolebebi wonasworuli korelaciuri funqciebisTvis <strong>da</strong> mesame Tavis$3.1_$3.4_ebSi ganxilul modelebze <strong>da</strong>yrdnobiT miRebuli Sedegebi(gamoyvanili formulebi: rogorc zogadi, aseve miaxloebiTi) SesaZleblobasiZleva ga<strong>da</strong>ugvarebel, farTozonian, erTgvarovan (polarul)naxevargamtarebSi, ionur <strong>da</strong> kovalentur kristalebSi_eleqtronuli<strong>da</strong> polaronuli gamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturuli dreifuli Zvradobiswrfivi kvanturi Teoriis agebas_kvanturi dinamiuri sistemebissxva modelTaTvisac, romlebic urTierTqmedeben fononebTan (<strong>eleqtronebis</strong>gabneva arapolarul optikur fononebze, piezoeleqtuli gabneva,polaronis fm. <strong>da</strong> sxva)._<strong>eleqtronebis</strong>Tvis erTi zonis miaxloebaSi,dispersiis rogorc zogadi, aseve paraboluri kanonis dros <strong>da</strong>fononebis dispersiis izotropuli kanonis SemTxvevaSi.<strong>da</strong>skvnebi1. sxva<strong>da</strong>sxva midgomebis-mowesrigebul operatorTa <strong>da</strong> liuvilissuperoperatoruli formalizmisa <strong>da</strong> proeqciuli operatoris meTodisgamoyenebiT, sawyisi korelaciebis gaTvaliswinebiT_gamoyvanilia axali,zusti, ganzogadoebuli kvanturi evoluciuri (kinetikuri) gantolebebidrois ormomentiani wonasworuli korelaciuri funqciebisTvis,dinamiuri qvesistemisTvis romelic urTierTqmedebs bozonurvelTan (TermostatTan). miRebul gantolebaTa <strong>da</strong>jaxebiTi integralebi(19)25


Seicaven rogorc wevrebs, romlebic aRweren namdvili korelaciebisevolucias droSi, aseve sawyisi korelaciebis evoluciur wevrebs,romlebic ganpirobebulia qvesistemis urTierTqmedebiT bozonur TermostatTandrois sawyis momentSi.2. SeSfoTebis Teoriis meore miaxloebaSi – qvesistemis TermostatTanurTierTqmedebis hamiltonianis mixedviT – napovnia ganzogadoebulikvanturi kinetikuri gantolebebi gamoricxuli bozonuriamplitudebiT korelaciuri funqciebisTvis, rogorc markoviseuli,ise aramarkoviseuli saxiT, romlebic Seicaven cxa<strong>da</strong>d gamoyofilsawyisi korelaciebis evoluciur wevrebs.3. eleqtron-fononuri sistemisTvis, frolixisa <strong>da</strong> akustikuripolaronis modelTaTvis, SeSfoTebis Teoriis meore miaxloebaSi,susti eleqtron-fononuri urTierTqmedebis SemTxvevaSi <strong>da</strong> erTi zonismiaxloebaSi eleqtronisaTvis gamoyvanilia <strong>da</strong> gamokvleulia markovissaxis kinetikuri gantolebebi eleqtronis siCqaris operatoriskomponentebis saSualo mniSvnelobebis diagonaluri matriculi elementebisaTvis,romlebic warmoadgenen bolcmanis tipis gantolebebs,sai<strong>da</strong>nac gamoricxulia fononuri amplitudebi. Gganxilulia eleqtronisaradrekadi gabnevis procesebi fononebze <strong>da</strong> <strong>da</strong>dgenilia, romganxilul modelebSi adgili aqvs relaqsaciur process korelaciurifunqciebis oscilaciebiT. Nnapovnia eleqtronis impulsis (siCqaris)relaqsaciis sixSireebis analizuri gamosaxulebebi kristalis <strong>da</strong>balitemperaturebis SemTxvevaSi. gamoTvlilia eleqtronis “siCqaresiCqareze”korelaciuri funqciebis milevis dekrementebi <strong>da</strong> oscilirebadifaqtorebi.4. gamokvleulia <strong>da</strong> <strong>da</strong>dgenilia, rom eleqtronis siCqaris (impulsis)mcire mniSvnelobebisaTvis, siCqaris relaqsaciis droebi(sixSireebi) ganxilul modelebSi ar aris <strong>da</strong>mokidebuli impulsissidideze. mcire siCqareebiTYmoZravi <strong>eleqtronebis</strong>Tvis Zalian <strong>da</strong>balitemperaturebis dros napovnia <strong>da</strong>balsixSiruli eleqtrogamtarobisa<strong>da</strong> eleqtronis dreifuli Zvradobis gamosaTvleli formulebi.5. frolixis polaronis modelSi miRebuli gamosaxulebebi eleqtronis<strong>da</strong>baltemperaturuli dreifuli Zvradobisa <strong>da</strong> dinamiurigamtarobiTvis warmoadgens osakas mier napovni Sedegis ganzogadoebasmcire intensivobis mqone <strong>da</strong>balsixSirul gareSe eleqtrul velSi,rac faqtiurad SesaZlebelia ganxiluli iqnas, rogorc drudes formulakuTri eleqtrogamtarobisTvis. napovnia agreTve statikuri( ω = 0) eleqtrogamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturuli dreifuli Zvradobisanalizuri gamosaxulebebi, rogorc frolixis, aseve akustikuripolaronis modelebSi.6. rogorc gamoTvlebi gviCvenebs, <strong>eleqtronebis</strong> gabnevisas polaruloptikur fononebze, <strong>da</strong>baltemperaturuli dreifuli ZvradobisTvis(dcmobility; ω = 0 ) miRebuli mniSvneloba 3-jer aRematebaZvradobis im mniSvnelobas, romelic miiReba bolcmanis kinetikurigantolebis gamoyenebiT <strong>da</strong> amoxsniT relaqsaciis drois miaxloebaSi.26


3 KmiRebuli Sedegi warmoadgens – “ BΤproblemis” – nawilobriv ga<strong>da</strong>wyvetasfrolixis polaronis <strong>da</strong>baltemperaturuli Zvradobis Teo-2 hω0riaSi.7. <strong>eleqtronebis</strong> gabnevisas akustikur fononebze (akustikuripolaronis modeli) miRebuli <strong>da</strong>baltemperaturuli dreifuli Zvradobis( ω = 0) mniSvneloba 2-jer naklebia Zvradobis im mniSvnelobaze,romelic aseve miiReba bolcmanis kinetikuri gantolebis amoxsnisasrelaqsaciis drois miaxloebaSi.8. ganxilul modelebSi napovnia agreTve eleqtronis dreifulZvradobaze temperaturuli Sesworebebi, romlebic ganpirobebulia sawyisikorelaciebis evoluciuri wevrebis arsebobiT gamoyvanilikinetikuri gantolebebis <strong>da</strong>jaxebiT integralebSi <strong>da</strong> naCvenebia, romes Sesworebebi warmoadgenen mcire sidideebs ganxiluli TeoriisfarglebSi.9. polaronis fgm-sTvis miRebuli kvanturi kinetikuri gantolebebieleqtruli denis operatoris komponentebis (polaronisimpulsis) drois ormomentiani wonasworuli korelaciuri funqciebisTvisgamoyenebulia polaronis dreifuli Zvradobisa <strong>da</strong>eleqtrogamtarobis tenzoris gamosaTvlelad. Gganxilul erTzonianizotropul SemTxvevaSi, markoviseul miaxloebaSi polaronis dinamikisTvis,napovnia miaxloebiTi gamosaxulebebi korelaciuri funqciebisTvis.10. kristalis Zalian <strong>da</strong>bali temperaturebis SemTxvevaSi gamoyvaniliabolcmanis tipis kinetikuri gantoleba korelaciuri funqciisdiagonaluri matriculi elementisTvis, romelic Seesabamebapolaronis ZiriTad mdgomareobas. gamokvleulia polaronis aradrekadigabnevis procesebi fononebze. napovnia impulsis relaqsaciissixSiris (drois) analizuri gamosaxuleba <strong>da</strong> <strong>da</strong>dgenilia, rom mciresiCqariT moZravi polaronisTvis impulsis relaqsaciis sixSire (dro)ar aris <strong>da</strong>mokidebuli impulsis sidideze.11. kubos wrfivi reaqciis Teoriis gamoyenebiT miRebulia <strong>da</strong>balsixSirulieleqtrogamtarobis tenzoris analizuri gamosaxulebaeleqtron-fononuri sistemisaTvis erTzonian miaxloebaSi <strong>da</strong> fononebisdispersiis zogadi (izotropuli) kanonis SemTxvevaSi. gamoTvliliapolaronis <strong>da</strong>baltemperaturuli dreifuli Zvradoba fgm-Si. ammodelSi napovnia agreTve temperaturuli Sesworeba polaronis dreifulZvradobaze, romelic ganpirobebulia sawyisi korelaciebisevoluciuri wevrebis arsebobiT miRebuli kinetikuri gantolebebis<strong>da</strong>jaxebiT integralebSi, <strong>da</strong> <strong>da</strong>sabuTebulia, rom es temperaturuliSesworeba warmoadgens mcire sidides.12. ganxilulia <strong>da</strong> gaanalizebulia polaronis <strong>da</strong>baltemperaturulidreifuli Zvradobis yofaqceva susti ( α < 1) <strong>da</strong> Zlieri(α >>1) eleqtron-fononuri urTierTqmedebis zRvrul SemTxvevebSi.susti eleqtron-fononuri urTierTqmedebis SemTxvevaSi ( MGF→ 0) , rodesacpolaronis fgm ga<strong>da</strong>dis polaronis frolixis modelSi, pola-27


onis <strong>da</strong>baltemperaturuli dreifuli ZvradobisTvis (γ >>1; ω =0)vRebulobT iseTive miSvnelobas, rogoric napovnia polaronis frolixismodelSi. Zlieri eleqtron-fononuri urTierTqmedebis SemTxvevaSi( MGF→∞), rodesac polaronis fgm aRadgens polaronis pekarisnaxevradklasikur Teorias, <strong>da</strong>baltemperaturuli dreifuli Zvradobis313yofaqceva moicema Semdegi TanafardobiT: µGF~ e.exp(γ ) α ; (0;2h = m = ω = 1γ = β >> 1; ω =0); anu polaronis <strong>da</strong>baltemperaturuli Zvradoba Zlierieleqtron-fononuri urTierTqmedebis SemTxvevaSi ( α >> 1)izrdeba α -bmis mudmivas mecamete rigis proporciulad am mudmivas didi mniSvnelobebisdros, maSin rodesac polaronis pekaris TeoriaSi <strong>da</strong>baltemperaturuliZvradoba izrdeba misi mexuTe rigis proporciulad:-µ ~ α5 Π; rodesac α >>1;( h = m = ω0= 1; β >> 1 ; ω = 0).13. sadisertacio naSromSi Catarebuli gamokvlevebi gviCvenebs,rom ganviTarebul meTodebs, romlebic <strong>da</strong>fuZnebulia kinetikuri gantolebebismiRebaze wonasworuli korelaciuri funqciebisTvis <strong>da</strong> maTgamoTvlaze, gansxvavebiT sxva midgomebisgan, ar mivyavarT ganSladiwevrebisagan Sedgenili usasrulo mwkrivebis ajamvis aucileblobas-Tan kvazinawilakis (eleqtronis, polaronis) urTierTqmedebis mixedviTfononebTan, kristalze modebuli gareSe eleqtruli velis <strong>da</strong>bali( ω → 0) sixSireebis SemTxvevaSi.naSromSi <strong>da</strong>sabuTebulia, rom arsebuli sawyisi korelaciebisevolucia <strong>da</strong> korelaciuri funqciebis oscilaciebi drois mixedviT,romlebic ganpirobebulia kvazinawilakis (zogad SemTxvevaSi kvanturidinamiuri qvesistemis) urTierTqmedebiT fononur (bozonur) velTandrois sawyis momentSi, gavlenas ar axdenen relaqsaciur procesebze<strong>da</strong> isini warmoadgenen Zvradobebze temperaturuli Sesworebebis ZiriTadmizezs (wyaros) ganxilul modelebSi.SUMMARYIn modern conditions a subject to research is a subject of electron and polarontransport phenomena study in solid states and condensed matter physics. Making electron andpolaron mobility and electrical conductivity quantum theory and quasi-particle kineticfeatures calculation remains one of the actual problem in modern theory of electron andpolaron. In the latest years a tendency of making materials of difficult molecular buildingand studying polaron features gave stimuli to implement a lot of theoretical research fordescribing autolocalized (polaron) matter. Polaron concepts, which represents a simpleexample of nonlinear quasi-particle, has great importance and is highly used in solid statesand condensed matter physics and especially it is closely connected to the fun<strong>da</strong>mentalproblems of quantum dynamical systems theory and to the subjects of quantum theory of afield. In the latest period it became actual to research subjects of electron-phonon system andpolaron kinetic on the base of Kubo linear response theory and to build correct quantumtheory of electron and polaron transfer phenomena and calculation of mechanical coefficients(mobility, electrical conductivity) in semiconductors and ionic crystals.28


The aim of thesis work is to receive and research new, exact generalized quantumkinetic equations for time correlation functions for some quantum dynamical systems of solidphysics, which interacts with phonon field (electron-phonon system, Frohlich and acousticalpolaron models, polaron generalized model of Feynman) and on the base of such modelsbuilding of consecutive, correct electron and polaron low- frequency conductivity and lowtemperaturedrift mobility quantum theory for non degenerated wide-band semiconductorsand ionic crystals based on Kubo linear response and perturbation theory and calculation ofmechanical coefficients transport (mobility, electrical conductivity) for above mentionedquantum subsystems models.The thesis work discusses two method of approach for new, exact generalizedquantum kinetic equations for double-time equilibrium correlation functions for quantumdynamical systems, which interacts with boson (phonon) field (thermostat).The first method of approach is based on ordered operators formalism andchronological and antichronological T-product method; and the second method of approachwhich is based on Liouville superoperative formalism and projection operator method.The first chapter of the work generally gives a short brief. In the first paragraph of thischapter deals with model Hamiltonian kind of dynamical systems, which interact with boson(phonon) thermostat and there are discussed some actual examples of quantum dissipative andopen nonequilibrium modeling systems and from different fields of modern physics, whichbecame the subject of intensive research and learn in the latest 30-40 years. The spectrum ofthe wide research contained subjects of metals’ electrical conductivity and superconductivitytheories, subjects of metal alloy and cold “metal glasses” electronic theory; subjects of weekand strong localization and strong inhomogeneous substances electrical conductivity theoryin disordered systems physics; aspects of laser radiation and superradiation theory aspects inquantum radiophysics; subjects of magnetic polaron and fluctuon (phason) and etc inmagnetic substances (environment) and others. The second paragraph deals withdynamically disordered system - electron-phonon system and electron interaction withacoustical and polar optical phonons and gives general introduction of Hamiltonian ofelectron-phonon system (Frohlich - Pekar type Hamiltonian), Hamiltonians of electronacoustical and polar optical phonons interaction and short brief of deformation potentialmethod. The third part of the work deals with large radius polaron models. There arereviewed polaron Frohlich and Pekary models and polaron Feynman oscillator andgeneralized Feynman models there. The same paragraph deals with a new approach forpolaron systems thermodynamics and kinetic subjects, developed in latest years – orderedoperators formalism, T-product method and phonon operators elimination method fromequilibrium and nonequilibrium average value – physical quantity characteristic for electronphononsystem. The advantage of a new method of approach in some occasions to at studyingkinetic subjects of electron-phonon system. The fourth paragraph deals with several principalsubjects of physical kinetics of dynamical systems, which interact with phonon (boson) field.There is given review of very important and principal subject such as opportunity of shortendescription at evolution (kinetic) equation for K-type dynamical systems (for classic andquantum as well), which is not based of a hypothesis about usage of initial correlationsweakness and random phase approximation (RPA). There is described those basic schedulesand methods, which lead us to Boltzmann type kinetic equation and master equation there.The chapter deals with such basic principal difficulties, which are arisen at calculation ofdrift mobilities for above mentioned models, as according to Boltzmann kinetic equation andKubo linear response theory and also at using some methods of linear and nonlinearconductivity theories (nonequilibrium density matrix and balance equation methods).29


The second chapter of thesis work deals with general question – to receive exact,generalized, quantum evolutionary equations for equilibrium correlation and Green functionsof dynamical subsystems, which interacts with boson (phonon) thermostat. The firstparagraph deals with ordered operators formalism and T-product method. The secondparagraph deals with new and exact quantum evolutional (kinetic) initial correlationsweakness principles equations for without random phase approximation usage and doubletimeequilibrium correlation and Green retarded functions, with eliminated boson amplitudes.The fourth paragraph deals with new and exact generalized quantum kinetic equations fordouble-time equilibrium correlation and Green functions been found by using Liouvillesuperoperative formalism and projection operator method. Unlike kinetic equations forcorrelation functions, received by different authors in scientific literature, integrals ofevolutional equations presented in this work contain additional members, which describeinitial correlations evolution in the period of time and which are caused by subsysteminteraction with boson thermostat in initial moment of time. The third and fifth paragraphsdiscuss Markov method of approach for subsystem dynamics and accordingly by the help ofboth formalism and methods there has been found approximately quantum kinetic equationsfor correlation functions with eliminated boson amplitudes and initial correlation descriptionand additional members in collission integrals. Researches and results have been conducted inthis chapter of the work give opportunity for better and wider studying of kinetic phenomena,which take place in dynamical systems and which interact with boson field.Subjects of electron and polaron transport phenomena quantum theories in solid states– in semiconductors and ionic crystals – have been researched in the third chapter of thesiswork. All four paragraphs of the same work are dedicated to electron and polaron lowfrequencyconductivity and low-temperature drift mobility quantum theory, which is based onthe above mentioned models of quantum dynamical systems, Kubo linear response andperturbation theory and on quantum kinetic equations for equilibrium correlation functionspresented in the second chapter. The first paragraph researches Markovian type kineticequations for correlation functions of electron “velocity – on velocity” in relaxation timeapproximation and there has been found decrements of <strong>da</strong>mping correlation functions andoscillation factors; for electron-phonon systems in the case of weak electron-phononinteraction in one band approximation there has been received analyze image of lowfrequencyelectrical conductivity tensor and low-temperature drift mobility of electron in thecase of anisotropy has been calculated there – conductivity band is of electron velocity. Thesecond and third paragraphs deals with several subjects of electronic transport phenomena inFrohlich and acoustical polaron models. There have been found formulas for calculating driftmobility and low-frequency conductivity at low-temperatures for electron in such models.Generalization of Osaka result for electron low-temperature mobility and low-frequencyconductivity in electric field are received in polaron Frohlich model. There is given partial3 K Tdecision for “ Bproblem” in Frohlich polaron low-temperature mobility theory and is2 hω0shown, that meaning of mobility given in this work excels three times those meaning ofmobility which is received by Boltzmann kinetic equation in relaxation time approximation.In acoustical polaron model (at scattered electron on acoustical phonons) meaning of lowtemperaturemobility is two times less than the meaning of mobility, which is also received byBoltzmann equation in relaxation time approximation. The fourth paragraph of the samechapter deals researches several subjects of polaron kinetic in generalized Feynman modeland kinetic equations are solved for polaron “momentum-on momentum” equilibrium30


correlation functions; there is calculated frequency of polaron momentum relaxation(relaxation time) at low temperature crystal and analyze image of low-frequency electricalconductivity tensor (dissipative part) is received; there is found polaron low-temperature driftmobility meaning there. There is analyzed polaron low-temperature mobility behavior in theevent of electron phonon interaction there and there is found mobility dependence oncoupling constant in the case of strong electron-phonon interaction and different behavior oflow-temperature mobility according to the degree of coupling constant by polaron Pekarmodel is established. The work also calculates temperature corrections on electron andpolaron low-temperature mobilitys in the discussed models and there is shown, that thesecorrections represent small quantities within discussed theory and approaches has been usedthere.disertaciis ZiriTadi Sedegebi gamoqveynebuliaSemdeg SromebSi:1. ???? ?.?., ????? ?.?. ??????????? ???????? ? ?????????? ?????? ??????????? ?????? ????????????. 24-? ?????????? ????????? ?? ?????? ????????????????. ?????? ????????: ????? II: ??????????? ??????? ??? ??????????????????. ???????, 8-10 ????????, 1986 ?., ???. 201-202.2. ????? ?.?., ???? ?.?. ? ?????? ???????? ????????. ?????????? ???????????:???-???????? ???????? ?????????????? ??????. ???????, 14-17 ??? 1991 ?.??????? ?????????, ???. 1-140. ?????? ????????, ???. 83.3. Kotiya B.A., Los’ V.F. Exact equations for subsystem correlation functions anddensity matrix. The 18th IUPAP International Conference on Statistical Physics.Berlin, 2-8 August, 1992, Programme and Abstracts. Exact and Rigorous Results, p.133.4. Kotiya B.A., Los’ V.F. Exact equations for subsystem correlation functions anddensity matrix. Application in Polaron mobility. International Workshop “Polaronsand Applications”, May 23-31, 1992, Puschino, Russia. Abstracts, p. 18.5. Kotiya B.A., Los’ V.F. Exact equations for subsystem correlation functions anddensity matrix. Application in Polaron mobility. Proceedings in Nonlinear Science.Polarons and Applications. Ed. Lakhno V.D. (John Wiley and Sons, Chichester,1994), pp. 407-418 (impaqt. <strong>da</strong>tvirTvis mqone).6. Kotiya B.A., Los’ V.F. To the theory of transport Phenomena in open systems. TheNorwegian Academy of Technological Sciences. The Lars Onsager Symposium.Coupled Transport Processes and Phase Transitions. June 2-4, 1993,Trondheim,Norwey. Abstracts, p. 89.7. Kotiya B.A., Los’ V.F. Exact Equations for Correlation Functions and Density Matrixof a Subsystem Interacting with a Heat Bath and their Application in the PolaronMobility. European physical Society. Eps9. Trends in Physics. Firenze. Italy.September 14-17, 1993. Abstracts. Symposium 29. Statistical Machanics: RigorousResults. ED. Systems, p. 130.31


8. <strong>kotia</strong> b. ga<strong>da</strong>tanis movlenebis Teoria eleqtron-fononuri sistemisaTvis.<strong>saqarTvelos</strong> <strong>teqnikuri</strong> <strong>universiteti</strong>s profesor-maswavlebelTasamecniero-<strong>teqnikuri</strong> konferencia. programa, 16-19 noemberi,Tbilisi, 1993 w. I-Teoriuli fizika, gv. 32.9. <strong>kotia</strong> b., losi v. polaronis Zvradobis TeoriisTvis. <strong>saqarTvelos</strong>mecnierebaTa akademiis moambe. t. 149, #1, 1994 w., Tbilisi, fizika,gv. 61-68.10. ????? ?.?., ???? ?.?. ? ?????? ?????????????????? ??????????? ????????? ??????? ????????????? ????????. ?????????? ???????? ????. ???????????????? ????. ????? ??????????, ?. 59, ? 8, 1995 ?.: ? ???????? ??????????????????? ????????? «?????????????????? ????????? ? ????????????? ???????????????? ????????». ??????. ?????? 1995 ?., ???.133-138 (impaqt.<strong>da</strong>tvirTvis mqone).11. Kotiya B.A., Los’ V.F. Low-Temperature Electron Mobility of Acoustical Polaron. InPerspectives of Polarons. Editors: G.N. Chuev and V.D. Lakhno. Russian Academy ofSciences. World Scientific. Singapore. New Jersey. London. Hong Kong. 1996, p.216-222 (impaqt. <strong>da</strong>tvirTvis mqone).12. Kotiya B.A., Los’ V.F. On the theory on Transport phenomena in the Polaron’sSystems. The 19th IUPAP International Conference on Statistical Physics. Xiamen31 July-4 August, 1995. Programme and Abstracts. Transport and Relaxation, p. 42.13. Kotiya B.A., Los’ V.F. Gigilashvili T.G. On the theory of transport phenomena in.electron-phonons’systems. The 20 th IUPAP International Conference on StatisticalPhysics. Paris, UNESCO, Sorbonne. July 20-25, 1998. Book of Abstracts,Nonequlibrium systems, p. 7.14. Kotiya B.A. On the theory of exact equations for correlation functions of the systemInteracting with a thermostat. Georgian Engineering News, 2005, ? 1, pp. 7-13.15. Kotiya B.A. On the theory of low-temperature electron mobility in the electronphononsystem and Frohlich’s model of the Polaron. Georgian Engineering News,2005, ? 2, pp. 11-21.16. ????? ?.?. ? ???????? ????????? ???????????? ??????, ????????????????? ????????? ?????. ????? I. ????????? ????????????? ?????????? ? ?????????????????? ???????? ????????. Georgian Engineering News, 2005, ? 4, ???. 7-1717. ????? ?.?. ? ???????? ????????? ???????????? ??????, ????????????????? ????????? ?????. ????? II. ???????????? ????????? ??? ????????????????????? ? ??????? ?????. Georgian Engineering News, 2006, ? 1, ???. 7-17.32


????? ?? ????? ?????????? ? ? ??? ???????? ????????????????? ? ?????? ? ??????? ???????????????????????? ? ? ? ???? ??????? ????????????? ?? ???? ???? ???? ?????? ?????????????????? ????????????? ????????? ???????????????? ???, 0175, ????????? ?2010 ??? ?© ???????? ? ????? ????? ?????, 2010 ?.


??????????? ????????? ????????????????????????? ? ? ??????? ?????????? ?????????????, ??????? ??? ?????????? ??? ???????? , ??? ????????? ??????????? ???? ?????? ???? ??? ????????? ??????? ??????? ???? :“?? ??? ??????? ?? ??? ???????? ????????? ???????? ??????????????? ????? ?? ????????????????? ?? ????? ??????? ????” ?????? ??? ????????????? ?????????? ????????? ?????????????„????????????? ????????? ??????????“ ??? ????????? ??????? ????????? ??? ???? ???? ???? ?????????????? ?????????? ?? .2010 ??? ???? ???????? ?:??????????:??????????:??????????:ii


??????????? ????????? ????????????2010 ??? ???????: ????? ???????????? ???: “?? ?????????? ?? ??? ???????? ????????????????? ??????? ???????? ????? ??????????????????? ??????? ??????? ????”?????????: ????????????? ????????? ????????????? ?????????????: ???? ????????? ???????: 2010 ?.?????????? ??? ???????????? ?? ???????????? ???????????????? ? ??????? ???? ??????????? ???????? ?????? ???????????????????? ???? ???????????? ? ???????? ?????????? ????????? ?????????? ????????? ? ???? ?????? ????????????? ????????????.??????? ??? ???????????? ?????????? ???????? ??????????? ? ???????? ?? ????? ? ???? ???????? ????? ???? ??? ??? ??????????????? ??? ????? ?? ?????? ????? ??? ???? ??????????? ????????? ?? ??????? ??????????????????? ??????.?????? ?????????, ??? ???????? ??????????? ? ????????????????? ????? ? ????? ??????????? ?? ?????????? ???????? (?????? ? ????? ????? ??????????, ???? ???? ????????? ?????? ??????????????????? ? ?????????? ??????????, ?????? ?? ??????? ???????????? ?????????? ?????? ??????) ?? ???? ? ??? ????? ?????????????????????.iii


???????E<strong>eleqtronebis</strong>a <strong>da</strong> polaronebis Zvradobis kvanturi Teoriisageba <strong>da</strong> kvazinawilakebis kinetikuri maxasiaTeblebis gamoTvlakvlav rCeba erT-erT aqtualur amocanad myari sxeulebisfizikaSi. ukanasknel periodSi did interss iwvevs kubos wrfivigamoZaxilis meTodze <strong>da</strong>yrdnobiT eleqtronuli <strong>da</strong> polaronuliga<strong>da</strong>tanis movlenebis koreqtuli kvanturi Teoriis ageba <strong>da</strong>meqanikuri koeficientebisH(Zvradoba, eleqtrogamtaroba) gamoTvlanaxevargamtarebsa <strong>da</strong> ionur kristalebSi.sadisertacio naSromis mizans warmoadgens-eleqtron-fononurisistemisTvis kvazinawilakis susti (frolixisa <strong>da</strong> akustikuripolaronis modelebi) <strong>da</strong> Zlieri (polaronis feinmanis ganzogadoebulimodeli (fgm)) urTirTqmedebis SemTxvevaSi fononurvelTan - axali,zusti, ganzogadoebuli kvanturi kinetikurigantolebebis miReba <strong>da</strong> gamokvleva droiTi wonasworuli korelaciurifunqciebisaTvis; am gantolebaTa gamoyenebiT, am modelTaTvisTanmimdevruli, koreqtuli eleqtronuli <strong>da</strong> polaronuli<strong>da</strong>baltemperaturuli dreifuli Zvradobis kvanturi Teoriisageba naxevargamtarebsa <strong>da</strong> ionur kristalebSi.sadisertacio naSromSi ganxilulia axali, zusti ganzogadoebulikvanturi kinetikuri gantolebebis miRebis ori midgomadrois ormomentiani wonasworuli korelaciuri funqciebisTvis:pirveli midgoma <strong>da</strong>fuZnebulia mowesrigebul operatorTa formalizmze<strong>da</strong> qronologiur <strong>da</strong> antiqronologiur T-namravlTa me-Todze, <strong>da</strong> meore midgoma eyrdnoba liuvilis superoperatorulformalizmsa <strong>da</strong> proeqciuli operatoris meTods.naSromis pirveli Tavis pirvel paragrafSi moyvaniliamodeluri hamiltonianis saxe dinamiuri sistemebisa, romlebicurTierTqmedeben bozonur (fononur) TermostatTan <strong>da</strong> ganxiluliazogierTi aqtualuri magaliTi kvanturi disipaciuri <strong>da</strong> Riaarawonasworuli modeluri sistemebisa Tanamedrove fizikissxva<strong>da</strong>sxva <strong>da</strong>rgi<strong>da</strong>n, romlebic gaxdnen intensiuri kvlevisa <strong>da</strong>Seswavlis sagani ukanaskneli 30-40 wlis ganmavlobaSi. meoreparagrafSi ganxilulia dinamiurad mouwesrigebeli sistema -eleqtron-fononuri sistema <strong>da</strong> eleqtronis urTierTqmedeba akustikur<strong>da</strong> polarul optikur fononebTan; moyvanilia eleqtronfononurisistemis hamiltonianis zogadi saxe (frolix-pekaristipis hamiltoniani), eleqtronis akustikur <strong>da</strong> polarul optikurfononebTan urTierTqmedebis hamiltonianTa saxeebi <strong>da</strong>mokled mimoxilulia agreTve deformaciis potencialis meTodi.didi radiusis mqone polaronTa modelebi – polaronis frolixisa<strong>da</strong> pekaris, feinmanis erToscilatoriani <strong>da</strong> fg modelebi –mimoxilulia mesame paragrafSi.amave paragrafSi ganxilulia agreTve ukanasknel wlebSiganviTarebuli <strong>da</strong> gamoyenebuli axali midgoma polaronuli sistemebisTermodinamikisa <strong>da</strong> kinetikis sakiTxebis gamokvlevebisasiv


– mowesrigebul operatorTa formalizmi, T-namravlTa meTodi <strong>da</strong>fononuri operatorebis gamoricxvis teqnika eleqtron-fononurisistemis maxasiaTebeli fizikuri sidideebis wonasworuli <strong>da</strong>arawonasworuli saSualo mniSvnelobebi<strong>da</strong>n. aRniSnulia zogierTSemTxvevaSi am axali midgomis upiratesoba eleqtron-fononurisistemis kinetikis sakiTxebis Seswavlisas, kontinualuriintegrirebis meTodTan Se<strong>da</strong>rebiT. meoTxe paragrafSi ganxiluliafizikuri kinetikis zogierTi principuli sakiTxi dinamiurisistemebisa, romlebic urTierTqmedeben fononur (bozonur) vel-Tan. mimoxilulia mniSvnelovani <strong>da</strong> principuli sakiTxi Κ -tipisdinamiur sistemebSi (rogorc klasikuris, aseve kvanturisTvis),evoluciuri gantolebebis gamoyvanis dros Semoklebuli aRwerisSesaZleblobaze, romelic ar eyrdnoba sawyisi korelaciebisSesustebisa <strong>da</strong> SemTxveviTi fazebis miaxloebis (Sfm) hipoTezas.aRwerilia ZiriTadi sqemebi <strong>da</strong> meTodebi, romlebsac mivyavarTbolcmanis saxis kinetikuri gantolebisa <strong>da</strong> ZiriTadi kinetikurigantolebis povnamde. ganxilulia is ZiriTadi principuli xasiaTissirTuleebi, romlebic warmoiSvebian eleqtron-fononurisistemisa <strong>da</strong> polaronis zemoTmoyvanil modelTaTvis dreifuliZvradobebis gamoTvlisas, gamomdinare rogorc bolcmanis kinetikurigantolebi<strong>da</strong>n <strong>da</strong> kubos wrfivi reaqciis Teorii<strong>da</strong>n, aseveeleqtrogamtarobis wrfivi <strong>da</strong> arawrfivi Teoriis zogierTi sxvameTodis (arawonasworuli simkvrivis matricis meTodi, balansisgantolebis meTodi) gamoyenebisas.sadisertacio naSromis meore Tavi originaluri xasiaTisaa.am TavSi <strong>da</strong>smulia zogadi amocana –dinamiuri qvesistemisTvis,romelic urTierTqmedebs bozonur (fononur) TermostatTanaxali,zusti, ganzogadoebuli kvanturi evoluciuri gantolebebismiReba wonasworuli korelaciuri <strong>da</strong> grinis funqciebisTvis.pirvel paragrafSi ganxilulia mowesrigebul operatorTa formalizmi<strong>da</strong> T-namravlTa meTodi. meore <strong>da</strong> meoTxe paragrafebSigamoyvanilia axali, zusti ganzogadoebuli kvanturi evoluciurigantolebebi drois ormomentiani wonasworuli korelaciuri<strong>da</strong> grinis <strong>da</strong>gvianebuli funqciebisTvis,liuvilis superoperatoruliformalizmisa <strong>da</strong> proeqciuli operatoris meTodisgamoyenebiT,sawyisi korelaciebis Sesustebis principisa <strong>da</strong> Sfm-s gamoyenebisgareSe. GgansxvavebiT samecniero literaturaSi sxva<strong>da</strong>sxvaavtorTa mier miRebuli kinetikuri gantolebebisagan korelaciurifunqciebisTvis, naSromSi gamoyvanili evoluciuri gantolebebis<strong>da</strong>jaxebiTi integralebi Seicaven <strong>da</strong>matebiT wevrebs,romlebic aRweren sawyisi korelaciebis evolucias droSi, <strong>da</strong>romlebic ganpirobebulia qvesistemis urTierTqmedebiT bozonurTermostatTan drois sawyis momentSi. mesame <strong>da</strong> mexuTe paragrafebSiganxilulia markoviseuli miaxloeba qvesistemis dinamikis-Tvis <strong>da</strong> Sesabamisad orive formalizmisa <strong>da</strong> meTodis <strong>da</strong>xmarebiTnapovnia SeSfoTebis Teoriis meore miaxloebaSi kvanturi kinetikurigantolebebi korelaciuri funqciebisTvis gamoricxuli bozonuriamplitudebiT <strong>da</strong> sawyisi korelaciebis evoluciis aRmweri<strong>da</strong>matebiTi wevrebiT <strong>da</strong>jaxebiT integralebSi.v


eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis kvanturiTeoriis sakiTxebi – naxevargamtarebsa <strong>da</strong> ionur kristalebSi– ganxilulia <strong>da</strong> gamokvleulia sadisertacio naSromismesame TavSi. am Tavis oTxive paragrafi eZRvneba eleqtronuli<strong>da</strong> polaronuli <strong>da</strong>balsixSiruli gamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturulidreifuli Zvradobis kvantur Teorias, romelic <strong>da</strong>fuZnebuliakubos wrfivi reaqciis Teoriaze, kvantur dinamiuri sistemebiszemoTmiTiTebul modelebze, <strong>da</strong> wina TavSi miRebul kvanturkinetikur gantolebebze. pirvel paragrafSi gamokvleulia<strong>da</strong> amoxsnilia relaqsaciis drois miaxloebaSi markovis saxiskinetikuri gantolebebi eleqtronis “siCqare-siCqareze” korelaciurifunqciebisTvis; miRebulia <strong>da</strong>balsixSiruli gamtarobistenzoris analizuri gamosaxuleba <strong>da</strong> gamoTvlilia eleqtronis<strong>da</strong>baltemperaturuli dreifuli Zvradoba eleqtron-fononurisistemisTvis erTi zonis miaxloebaSi izotropul SemTxvevaSi –eleqtronis siCqarisa <strong>da</strong> fononebis dispersiis nebismieri zogadi,izotropuli kanonis SemTxvevaSi. meore <strong>da</strong> mesame paragrafeb-Si napovnia <strong>da</strong>balsixSiruli eleqtrogamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturulidreifuli Zvradobis gamosaTvleli formulebifrolixisa <strong>da</strong> akustikuri polaronis modelebSi. polaronisfrolixis modelSi miRebulia osakas Sedegis ganzogadoebaeleqtronis <strong>da</strong>baltemperaturuli dreifuli ZvradobisTvis3 K T<strong>da</strong>balsixSirul gareSe eleqtrul velSi; moyvanilia “ B2 hω0problemis” nawilobrivi ga<strong>da</strong>wyveta frolixis polaronis <strong>da</strong>baltemperaturuliZvradobis TeoriaSi <strong>da</strong> naCvenebia, rom naSromSimiRebuli Zvradobis mniSvneloba 3-jer aRemateba Zvradobisim mniSvnelobas, romelic miiReba bolcmanis kinetikuri gantolebisamoxsniT relaqsaciis drois miaxloebaSi. akustikuri polaronismodelSi naSromSi napovni eleqtronis <strong>da</strong>baltemperaturulidreifuli Zvradobis mniSvneloba 2-jer naklebiaZvradobis im mniSvnelobaze, romelic aseve miiReba bolcmanisgantolebis amoxsniT relaqsaciis drois miaxloebaSi. meoTxe paragrafSiGgamoyvanilia <strong>da</strong> amoxsnilia (relaqsaciis droismiaxloebaSi) kinetikuri gantolebebi polaronis “impulsiimpulsze”wonasworuli korelaciuri funqciebisTvis fgm-Si. mi-Rebulia <strong>da</strong>balsixSiruli eleqtrogamtarobis tenzoris analizurigamosaxuleba <strong>da</strong> gamoTvlilia polaronis <strong>da</strong>baltemperaturulidreifuli Zvradoba. napovnia Zvradobis <strong>da</strong>mokidebulebaeleqtron-fononuri urTierTqmedebis (bmis) mudmivaze Zlierieleqtron-fononuri urTierTqmedebis SemTxvevaSi, <strong>da</strong> <strong>da</strong>dgenilia<strong>da</strong>baltemperaturuli Zvradobis gansxvavebuli yofaqceva (bmismudmivas rigis mixedviT) polaronis pekaris modelTan Se<strong>da</strong>rebiT.naSromSi gamoTvlilia aseve temperaturuli Sesworebebieleqtronisa <strong>da</strong> polaronis <strong>da</strong>baltemperaturul dreiful Zvradobebzeganxilul modelebSi, <strong>da</strong> naCvenebia, rom es Sesworebebiwarmoadgenen mcire sidideebs ganxiluli Teoriisa <strong>da</strong> gamoyenebulimiaxloebebis farglebSi.vi


AbstractIn modern conditions a subject to research is a subject of electron and polarontransport phenomena study in solid states and condensed matter physics. Makingelectron and polaron mobility and electrical conductivity quantum theory and quasiparticlekinetic features calculation remains one of the actual problem in moderntheory of electron and polaron. In the latest years a tendency of making materials ofdifficult molecular building and studying polaron features gave stimuli to implement alot of theoretical research for describing autolocalized (polaron) matter. Polaronconcepts, which represents a simple example of nonlinear quasi-particle, has greatimportance and is highly used in solid states and condensed matter physics andespecially it is closely connected to the fun<strong>da</strong>mental problems of quantum dynamicalsystems theory and to the subjects of quantum theory of a field. In the latest period itbecame actual to research subjects of electron-phonon system and polaron kinetic onthe base of Kubo linear response theory and to build correct quantum theory ofelectron and polaron transfer phenomena and calculation of mechanical coefficients(mobility, electrical conductivity) in semiconductors and ionic crystals.The aim of thesis work is to receive and research new, exact generalizedquantum kinetic equations for time correlation functions for some quantum dynamicalsystems of solid physics, which interacts with phonon field (electron-phonon system,Frohlich and acoustical polaron models, polaron generalized model of Feynman) andon the base of such models building of consecutive, correct electron and polaron lowfrequencyconductivity and low-temperature drift mobility quantum theory for nondegenerated wide-band semiconductors and ionic crystals based on Kubo linearresponse and perturbation theory and calculation of mechanical coefficients transport(mobility, electrical conductivity) for above mentioned quantum subsystems models.The thesis work discusses two method of approach for new, exact generalizedquantum kinetic equations for double-time equilibrium correlation functions forquantum dynamical systems, which interacts with boson (phonon) field (thermostat).The first method of approach is based on ordered operators formalism andchronological and antichronological T-product method; and the second method ofapproach which is based on Liouville superoperative formalism and projectionoperator method.The first chapter of the work generally gives a short brief. In the firstparagraph of this chapter deals with model Hamiltonian kind of dynamical systems,which interact with boson (phonon) thermostat and there are discussed some actualexamples of quantum dissipative and open nonequilibrium modeling systems andfrom different fields of modern physics, which became the subject of intensiveresearch and learn in the latest 30-40 years. The spectrum of the wide researchcontained subjects of metals’ electrical conductivity and superconductivity theories,subjects of metal alloy and cold “metal glasses” electronic theory; subjects of weekand strong localization and strong inhomogeneous substances electrical conductivitytheory in disordered systems physics; aspects of laser radiation and superradiationtheory aspects in quantum radiophysics; subjects of magnetic polaron and fluctuon(phason) and etc in magnetic substances (environment) and others. The secondparagraph deals with dynamically disordered system - electron-phonon system andelectron interaction with acoustical and polar optical phonons and gives generalintroduction of Hamiltonian of electron-phonon system (Frohlich - Pekar typeHamiltonian), Hamiltonians of electron acoustical and polar optical phononsinteraction and short brief of deformation potential method. The third part of the workvii


deals with large radius polaron models. There are reviewed polaron Frohlich andPekary models and polaron Feynman oscillator and generalized Feynman modelsthere. The same paragraph deals with a new approach for polaron systemsthermodynamics and kinetic subjects, developed in latest years – ordered operatorsformalism, T-product method and phonon operators elimination method fromequilibrium and nonequilibrium average value – physical quantity characteristic forelectron-phonon system. The advantage of a new method of approach in someoccasions to at studying kinetic subjects of electron-phonon system. The fourthparagraph deals with several principal subjects of physical kinetics of dynamicalsystems, which interact with phonon (boson) field. There is given review of veryimportant and principal subject such as opportunity of shorten description atevolution (kinetic) equation for K-type dynamical systems (for classic and quantumas well), which is not based of a hypothesis about usage of initial correlationsweakness and random phase approximation (RPA). There is described those basicschedules and methods, which lead us to Boltzmann type kinetic equation and masterequation there. The chapter deals with such basic principal difficulties, which arearisen at calculation of drift mobilities for above mentioned models, as according toBoltzmann kinetic equation and Kubo linear response theory and also at using somemethods of linear and nonlinear conductivity theories (nonequilibrium density matrixand balance equation methods).The second chapter of thesis work deals with general question – to receiveexact, generalized, quantum evolutionary equations for equilibrium correlation andGreen functions of dynamical subsystems, which interacts with boson (phonon)thermostat. The first paragraph deals with ordered operators formalism and T-productmethod. The second paragraph deals with new and exact quantum evolutional(kinetic) initial correlations weakness principles equations for without random phaseapproximation usage and double-time equilibrium correlation and Green retardedfunctions, with eliminated boson amplitudes. The fourth paragraph deals with new andexact generalized quantum kinetic equations for double-time equilibrium correlationand Green functions been found by using Liouville superoperative formalism andprojection operator method. Unlike kinetic equations for correlation functions,received by different authors in scientific literature, integrals of evolutional equationspresented in this work contain additional members, which describe initial correlationsevolution in the period of time and which are caused by subsystem interaction withboson thermostat in initial moment of time. The third and fifth paragraphs discussMarkov method of approach for subsystem dynamics and accordingly by the help ofboth formalism and methods there has been found approximately quantum kineticequations for correlation functions with eliminated boson amplitudes and initialcorrelation description and additional members in collission integrals. Researches andresults have been conducted in this chapter of the work give opportunity for better andwider studying of kinetic phenomena, which take place in dynamical systems andwhich interact with boson field.Subjects of electron and polaron transport phenomena quantum theories insolid states – in semiconductors and ionic crystals – have been researched in thethird chapter of thesis work. All four paragraphs of the same work are dedicated toelectron and polaron low-frequency conductivity and low-temperature drift mobilityquantum theory, which is based on the above mentioned models of quantumdynamical systems, Kubo linear response and perturbation theory and on quantumkinetic equations for equilibrium correlation functions presented in the secondchapter. The first paragraph researches Markovian type kinetic equations forviii


correlation functions of electron “velocity – on velocity” in relaxation timeapproximation and there has been found decrements of <strong>da</strong>mping correlation functionsand oscillation factors; for electron-phonon systems in the case of weak electronphononinteraction in one band approximation there has been received analyze imageof low-frequency electrical conductivity tensor and low-temperature drift mobility ofelectron in the case of anisotropy has been calculated there – conductivity band is ofelectron velocity. The second and third paragraphs deals with several subjects ofelectronic transport phenomena in Frohlich and acoustical polaron models. There havebeen found formulas for calculating drift mobility and low-frequency conductivity atlow-temperatures for electron in such models. Generalization of Osaka result forelectron low-temperature mobility and low-frequency conductivity in electric field are3 K Treceived in polaron Frohlich model. There is given partial decision for “ B2 hω0problem” in Frohlich polaron low-temperature mobility theory and is shown, thatmeaning of mobility given in this work excels three times those meaning of mobilitywhich is received by Boltzmann kinetic equation in relaxation time approximation. Inacoustical polaron model (at scattered electron on acoustical phonons) meaning oflow-temperature mobility is two times less than the meaning of mobility, which is alsoreceived by Boltzmann equation in relaxation time approximation. The fourthparagraph of the same chapter deals researches several subjects of polaron kinetic ingeneralized Feynman model and kinetic equations are solved for polaron “momentumonmomentum” equilibrium correlation functions; there is calculated frequency ofpolaron momentum relaxation (relaxation time) at low temperature crystal and analyzeimage of low-frequency electrical conductivity tensor (dissipative part) is received;there is found polaron low-temperature drift mobility meaning there. There isanalyzed polaron low-temperature mobility behavior in the event of electron phononinteraction there and there is found mobility dependence on coupling constant in thecase of strong electron-phonon interaction and different behavior of low-temperaturemobility according to the degree of coupling constant by polaron Pekar model isestablished. The work also calculates temperature corrections on electron and polaronlow-temperature mobilitys in the discussed models and there is shown, that thesecorrections represent small quantities within discussed theory and approaches hasbeen used there.ix


SinaarsiSinaarsi.......................................................................................................................xnaxazebis nusxa .....................................................................................................xiiiSesavali.........................................................................................................................................................xivTavi I. dinamiuri sistemebi, romlebic urTierTqmedebenTermostatTan (bozonur velTan)........................................................................................231.1. kvanturi disipaciuri <strong>da</strong> Ria arawonasworuli modelurisistemebi (zogierTi magaliTi) ..................................................................... 251.1.1. fermionuli sistema .............................................................................. 251.1.2. Txevadi metalis an Senadnobis modeli.......................................... 251.1.3. nawilaki, romelic urTierTqmedebs garemosTan......................... 271.1.4. eleqtron-minarevuli sistema............................................................... 301.1.5. dikes modelebi gamosxivebis TeoriaSi........................................... 311.1.6. eleqtronebi magnetikSi, romlebic urTierTqmedebenkristalis magnitur qvesistemasTan ........................................................... 331.2. eleqtron-fononuri sistema. eleqtronis urTierTqmedebaakustikur <strong>da</strong> polarul optikur fononebTan....................................... 361.2.1. eleqtronis urTierTqmedeba kristaluri mesris akustikurrxevebTan. deformaciis potencialis meTodi........................................ 371.2.2. eleqtronis urTierTqmedeba polarul optikur fononebTan...................................................................................................................................... 391.3. polaronis amocana. didi radiusis mqone polaronismodelebi.................................................................................................................. 411.3.1. polaronis frolixisa <strong>da</strong> pekaris modelebi................................ 421.3.2. polaronis feinmanis modeli............................................................... 52x


1.3.3. polaronis feinmanis ganzogadoebuli modeli........................... 60(latinjer-lus modeli)................................................................................... 601.4. fizikuri kinetikis zogierTi sakiTxi dinamiuri sistemebisa,romlebic urTierTqmedeben fononur (bozonur) velTan................. 66Tavi II. ganzogadoebuli kvanturi evoluciuri gantolebebidrois ormomentiani wonasworuli korelaciuri funqciebisa <strong>da</strong>grinis funqciebisTvis dinamiuri qvesistemisa, romelicurTierTqmedebs TermostatTan (bozonur velTan).........................................822.1. mowesrigebul operatorTa formalizmi <strong>da</strong> T-namravlTameTodi....................................................................................................................... 822.2. zusti ganzogadoebuli kvanturi kinetikuri gantolebebiwonasworuli korelaciuri funqciebisa <strong>da</strong> grinisfunqciebisTvis...................................................................................................... 912.3. markoviseuli miaxloeba qvesistemis dinamikisTvismiaxloebiTi gantolebebi korelaciuri funqciebisTvis................ 952.4. ganzogadoebuli kvanturi evoluciuri gantolebebikorelaciuri funqciebisTvis Sfm-is gamoyenebis gareSe.proeqciuli operatoris meTodi.................................................................. 992.5. Termostatis bozonuri amplitudebis gamoricxva evoluciurigantolebi<strong>da</strong>n korelaciuri funqciisaTvis. markoviseulimiaxloeba qvesistemis dinamikisTvis........................................................ 103Tavi III. naxevargamtarebsa <strong>da</strong> ionuri kristalebSi eleqtronuli<strong>da</strong> polaronuli gamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturuli Zvradobiskvanturi Teoria <strong>da</strong>fuZnebuli kubos wrfivi gamoZaxilisTeoriaze........................................................................................................................................................1083.1.eleqtron-fononuri sistema. eleqtronis <strong>da</strong>balsixSirulieleqtrogamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturuli Zvradobis gamoTvlasusti eleqtron-fononuri urTierTqmedebis SemTxvevaSi114xi


3.2. eleqtronis Zvradoba frolixis polaronis modelSi............ 1173.3. eleqtronis Zvradoba akustikuri polaronis modelSisusti eleqtron –fononuri urTierTqmedebis SemTxvevaSi........ 1273.4 polaronis <strong>da</strong>baltemperaturuli Zvradoba feinmanisganzogadoebul modelSi............................................................................... 134<strong>da</strong>skvna..............................................................................................................................................................143gamoyenebuli literatura............................................................................. 146<strong>da</strong>narTibozonuri (fononuri) amplitudebis gamoricxva qronologiur<strong>da</strong> antiqronologiur T-namravlTa <strong>da</strong>xmarebiT................................... 153disertaciis TemasTan <strong>da</strong>kavSirebiT gamoqveynebulia SemdeginaSromebi............................................................................................................... 156xii


naxazebis nusxanax.1. potencialuri ormo, energetikuli doneebi<strong>da</strong> eleqtronis Ψ -talRuri funqcia pekarispolaronis modelSi---------------------------------------------------------------51nax.2. polaronis feinmanis modeli. eleqtroni,romelic <strong>da</strong>kavSirebulia “zambaris” meSveobiTmeore nawilakTan masiT M F ---------------------------------------------------56nax.3. V <strong>da</strong> W – variaciuli parametrebis yofaqceva,rogorc α-urTierTqmedebis (bmis) mudmivas funqciebi,polaronis feinmanis TeoriaSi-------------------------------------------- 58xiii


Sesavaliukanaskneli 50-60 wlis ganmavlobaSi didi yuradReba eTmobo<strong>da</strong>denis (muxtis) ga<strong>da</strong>mtanebis dinamiuri <strong>da</strong> kinetikuri TvisebebisSeswavlas myar sxeulebSi. zoga<strong>da</strong>d denis aseT ga<strong>da</strong>mtanebswarmoadgens sxva<strong>da</strong>sxva saxis polaronebi; TiToeuli maTgani moicavsgamtarobis eleqtrons (an xvrels) <strong>da</strong> maT mier gamowveulmesris struqturis deformacias. aseTi TvalsazrisiT gamtarobiseleqtroni (an xvreli) faqtiurad warmoadgens polaronszRvruli, susti deformaciis SemTxvevaSi. <strong>eleqtronebis</strong> <strong>da</strong> polaronebisdinamiuri <strong>da</strong> kinetikuri yofaqcevis Seswavla stimulirebuliiyo mravali eqsperimentuli masaliT, romelic exebo<strong>da</strong>ga<strong>da</strong>tanis movlenebis gamokvlevas myar sxeulebSi, romelTainterpretacia mraval SemTxvevaSi stan<strong>da</strong>rtuli zonuri TeoriisCarCoebSi Zalze rTuli iyo, gansakuTrebiT ionur kristalebSi<strong>da</strong> polarul naxevargamtarebSi. gar<strong>da</strong> amisa, ga<strong>da</strong>tanis movlenebiszogadi debulebebi kristalebSi arsebiTad iqna ganviTarebuliim fun<strong>da</strong>mentaluri gamokvlevebis safuZvelze, romelicasaxavs disipaciuri sistemebis dinamiur <strong>da</strong> kinetikur Tvisebebs<strong>da</strong> romlebSic mimdinareobs Seuqcevadi ga<strong>da</strong>tanis movlenebi. eleqtronuliga<strong>da</strong>tanis movlenebis Teoriis ganviTarebis aseTmapirobebma gamoiwvia mniSvnelovani zegavlena iseTi kvlevis areebisCamoyalibebaSi, rogoric aris – polaronuli ga<strong>da</strong>tanis movlenebi,eleqtronuli ga<strong>da</strong>tanis movlenebi Zlier (kvantur) magniturvelSi, eleqtronuli ga<strong>da</strong>tanis movlenebis Teoria magniturkristalebSi <strong>da</strong> mouwesrigebel garemoebSi (sistemebSi) <strong>da</strong> sxva.rogorc cnobilia, kristalebSi eleqtronuli ga<strong>da</strong>tanismovlenebis zonuri Teoria principSi <strong>da</strong>fuZnebulia sam ZiriTadkoncefciaze: 1) denis ga<strong>da</strong>mtanebi warmoadgens kvazinawilakebsgansazRvruli kvaziimpulsiT <strong>da</strong> dispersiis kanoniT. 2) denisga<strong>da</strong>mtanTa eleqtrogamtaroba <strong>da</strong> Zvradoba ganisazRvreba maTigabneviT kristalis idealuri mesris struqturis dinamiur <strong>da</strong>statikur <strong>da</strong>maxinjebebze (defeqtebze). 3) denis ga<strong>da</strong>mtanis Tavi-xiv


sufali ganarbenis sigrZe warmoadgens sasrul sidides <strong>da</strong> isbevrad aRemateba Sesabamisad kvazinawilakis de-broilis talRissigrZes. am pirobebis gaTvaliswinebiT denis ga<strong>da</strong>mtanTa gabnevaSeiZleba CaiTvalos rogorc “iSviaTi”. am debulebebi<strong>da</strong>ngamomdinare, denis ga<strong>da</strong>mtanTa yofaqceva kristalSi aRiwerebaalbaTuri ganawilebis funqciiT kvaziimpulsebis mixedviT,romelic ganisazRvreba, rogorc bolcman-bloxis kinetikurigantolebis amoxsna. ukanaskneli SeiZleba ganxiluli iqnas,rogorc balansis (uwyvetobis) gantoleba, romelSic gaTvaliswinebuliadenis ga<strong>da</strong>mtanTa ganawilebis funqciis cvlilebakristalSi, gamowveuli rogorc gareSe modebuli ZalebiszegavleniT, agreTve denis ga<strong>da</strong>mtanTa kvaziimpulsis ga<strong>da</strong>nawilebiT(cvlilebiT) gabnevis procesSi. aseTi gagebiT (Tu mxedvelobaSiar miviRebT dispersiis kanonis kvantur-meqanikur bunebas<strong>da</strong> denis ga<strong>da</strong>mtanebis gabnevis albaTurobas), ga<strong>da</strong>tanis movlenebisTeoria, romelsac xSirad uwodeben bolcmaniseuls, arsebi-Tad warmoadgens klasikurs <strong>da</strong> igi ar moicavs specifiur kvanturefeqtebs. amrigad, klasikur areebSi ga<strong>da</strong>tanis kinetikuri(meqanikuri) koeficientebis (Zvradoba, eleqtrogamtaroba) gamosa-Tvlelad gamoiyeneba denis ga<strong>da</strong>mtanebis arawonasworuli ganawilebisfunqciisaTvis kinetikuri gantoleba – bolcmanis gantoleba– romelic iTvaliswinebs denis (muxtis) matarebelTaurTierTqmedebas (gabnevas) kristaluri mesris rxevebze.ukanasknel wlebSi, eleqtronuli ga<strong>da</strong>tanis movlenebis gamokvlevebSimyari sxeulebis <strong>da</strong> naxevargamtarebis fizikaSi, ZalianfarTo gamoyeneba hpova ufro zogadma, alternatiulma midgomam,romelic <strong>da</strong>fuZnebulia kubos wrfivi reaqciis Teoriaze.am TeoriaSi - romelsac ga<strong>da</strong>mwyveti mniSvneloba aqvs wrfiv arawonasworulTermodinamikaSi – ga<strong>da</strong>tanis kinetikuri (meqanikuri)koeficientebi bunebrivad gamoisaxebian (aRiwerebian) droiTi korelaciurifunqciebiT. isini asaxaven sistemis reaqcias hamiltonianisSeSfoTebisas, romlis tipiur magaliTs warmoadgens eleqtrogamtaroba.kubo-grinis formulebi ga<strong>da</strong>tanis koeficientebi-xv


saTvis warmoadgenen kerZo SemTxvevas TanafardobaTa farToklasisa, romelic cnobilia fluqtuaciur-disipaciuri TeoremebissaxelwodebiT. am Teoremebis amsaxveli maTematikuri formulebiamyareben kavSirs mikroskopul <strong>da</strong> makroskopul <strong>da</strong>mzeradsidideebs Soris. wrfivi ga<strong>da</strong>tanis movlenebis ganxilvisas kubosformula “deni-denze” droiTi korelaciuri funqciisaTvis warmoadgensarsebiTad zust gamosaxulebas kvantur mravalnawilakovanformalizmSi, im gansxvavebiT bolcmanis kinetikuri gantolebisagan,rom araviTari <strong>da</strong>Sveba ar keTdeba gabnevis kveTis sididisSesaxeb denis ga<strong>da</strong>mtanebis (<strong>eleqtronebis</strong>) gabnevisas kristalurmesris rxevebze. un<strong>da</strong> aRiniSnos, rom tradiciulad eqvivalentobaskubos formulasa <strong>da</strong> bolcmanis gantolebas Sorismkacrad ikvleven mxolod denis ga<strong>da</strong>mtanebis susti gabneviszRvrul SemTxvevaSi kristaluri mesris rxevebze. rogorc cnobilia,kubos formula amyarebs kavSirs eleqtrogamtarobasa <strong>da</strong>droiT wonasworul korelaciur funqcia “deni-dens” Soris, romelicaris ornawilakovani (oTxwertilovani) grinis funqciismsgavsi, maSin, rodesac bolcmanis gantoleba warmoadgens – kinetikurgantolebas arawonasworuli ganawilebis funqciisaTvis,<strong>da</strong> romelic aris erTnawilakovani (orwertilovani) grinis funqciissaxis.Teoriuli gamokvlevebis Zalian didi raodenoba samecnieroliteraturaSi miZRvnili aris <strong>eleqtronebis</strong>a <strong>da</strong> polaronebiseleqtrogamtarobisa <strong>da</strong> Zvradobis gamoTvlaze naxevargamtarebsa<strong>da</strong> ionur kristalebSi. es gamokvlevebi <strong>da</strong>fuZnebuli arissxva<strong>da</strong>sxva Teoriul meTodebze – grinis funqciis teqnikaze,bolcmanis kinetikuri gantolebis Seswavlaze, TviTSeTanxmebulmeTodebze <strong>da</strong> sxv. rezultatebi miRebuli sxva<strong>da</strong>sxva meTodebisgamoyenebiT <strong>da</strong> Sesabamisad sxva<strong>da</strong>sxva miaxloebebze <strong>da</strong>yrdnobiT,Zireulad gansxvavdeba erTmaneTisagan. miuxe<strong>da</strong>vad imisa, rom<strong>eleqtronebis</strong> <strong>da</strong> polaronebis eleqtrogamtarobisa <strong>da</strong> ZvradobisgamoTvla warmoadgens erT-erT uZveles problemas myari sxeule-xvi


is fizikaSi, is mainc rCeba erT-erT urTules <strong>da</strong> Znel amocanadTeoriulad amoxsnis TvalsazrisiT.amgvarad, Tanamedrove pirobebSi kvlav aqtualurs warmoadgenssakiTxi <strong>eleqtronebis</strong> <strong>da</strong> polaronebis eleqtrogamtarobis<strong>da</strong> Zvradobis koreqtuli gamoTvlisa naxevargamtarebsa <strong>da</strong> ionurkristalebSi.rogorc cnobilia, efeqtur meTods urTierTqmed nawilakTasistemis kinetikuri maxasiaTeblebis gamoTvlisa warmoadgens wonasworulkorelaciur funqciaTa <strong>da</strong> grinis funqciebis meTodi.kubos wrfivi gamoZaxilis Teoriis upiratesoba arawonasworulistatistikuri meqanikis sxva midgomebTan Se<strong>da</strong>rebiT mdgomareobsimaSi, rom es Teoria saSualebas iZleva uSualod gamoyenebuliiqnas wonasworuli mravalnawilakovani meTodebi ga<strong>da</strong>tanis kinetikuri(meqanikuri) koeficientebis gamosaTvlelad myar sxeuleb-Si. am midgomis dros ZiriTad problemas warmoadgens wonasworulikorelaciuri funqciebis gamoTvla, romlebisTvisac iwerebakvanturi evoluciuri (kinetikuri) gantolebebi.myari sxeulebis fizikisa <strong>da</strong> arawonasworuli statistikurimeqanikis mravali amocanis ganxilvisas Seiswavleba mcire dinamiuriqvesistemis evolucia droSi, romelic imyofeba kontaqt-Si didi Tavisuflebis ricxvis mqone, Termodinamikur wonasworobaSimyof sistemasTan – TermostatTan.eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis gamokvlevisasmyar sxeulebSi kubos wrfivi gamoZaxilis Teoriaze<strong>da</strong>yrdnobiT, ZiriTad amocanas warmoadgens zusti ganzogadoebuli.kvanturi evoluciuri (kinetikuri) gantolebebis miReba droisormomentiani wonasworuli korelaciuri funqciebisTvis kvazinawilakebisaRmweri Sesabamisi dinamiuri sidideebisaTvis, rodesacxdeba am ukanasknelTa urTierTqmedeba (gabneva) kristalurimesris rxevebze (fononebze), <strong>da</strong> rodesac fononuri (bozonuri)veli ganixileba rogorc Termostati. samecniero literaturaSi,aseTi saxis gantolebebis misaRebad, rogorc wesi gamoiyenebaaprioruli hipoTeza – sawyisi korelaciebis Sesustebisxvii


principi, an msgavsi debulebebi – mag. SemTxveviTi fazebis miaxloeba(Sfm) – rodesac drois sawyisi momentisaTvis mTelisistemis (qvesistema plus Termostati) statistikuri operatorimoicema faqtorizebuli saxiT (mTeli sistemis statistikurioperatori ganixileba rogorc qvesistemisa <strong>da</strong> Termostatis statistikuroperatorTa pir<strong>da</strong>piri namravli). naTelia, rom aseTi<strong>da</strong>Svebebis Sedegad miRebuli ganzogadoebuli, kvanturi evoluciurigantolebebi wonasworuli korelaciuri funqciebisaTvisar aris zusti. amitom cxadia, rom zoga<strong>da</strong>d kvanturi disipaciurisistemebis ganxilvisas <strong>da</strong> kinetikuri movlenebis Seswavlisasmcire dinamiur sistemebSi, romlebic urTierTqmedeben bozonur(fononur) TermostatTan, kubos wrfivi gamoZaxilis TeoriisfarglebSi mkacri midgomis gansaviTareblad saWiroa zusti, ganzogadoebuli,kvanturi evoluciuri gantolebebis gamoyvana qvesistemisdinamiuri sidideebis wonasworuli korelaciuri funqciebisTvis.amrigad, eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebiskoreqtuli Teoriis asagebad <strong>da</strong> meqanikuri koeficientebis(mag. Zvradoba, eleqtrogamtaroba) gamosaTvlelad naxevargamtarebsa<strong>da</strong> ionur kristalebSi <strong>da</strong> agreTve eleqtron-fononuri sistemiskinetikis sakiTxebis gamosakvlevad kubos wrfivi reaqciisTeoriis CarCoebSi, aqtualurs warmoadgens amocana kvazinawilakebisdinamiuri sidideebisTvis drois ormomentiani wonasworulikorelaciuri funqciebisTvis zusti, ganzogadoebuli, kvanturievoluciuri gantolebebis miReba – sawyisi korelaciebis Sesustebisprincipisa <strong>da</strong> Sfm-is gamoyenebis gareSe.sadisertacio naSromis mizans warmoadgens:− myari sxeulebis fizikis zogierTi kvanturi dinamiuri sistemisTvis,romelic urTierTqmedebs fononur (bozonur) velTan(eleqtron-fononuri sistema, frolixis polaronis modeli,akustikuri polaronis modeli susti eleqtron-fononuri urTierTqmedebisSemTxvevaSi, polaronis fgm), mowesrigebul opera-xviii


torTa formalizmsa <strong>da</strong> T-namravlTa teqnikaze <strong>da</strong>yrdnobiT, agreTveliuvilis superoperatoruli formalizmisa <strong>da</strong> proeqciulioperatoris meTodis gamoyenebiT zusti, ganzogadoebulikvanturi evoluciuri (kinetikuri) gantolebebis miReba <strong>da</strong> gamokvlevadrois ormomentiani wonasworuli korelaciuri funqciebisTvisSfm-is gamoyenebis gareSe.− Aam modelebze <strong>da</strong>yrdnobiT Tanmimdevruli, srulyofilieleqtronuli <strong>da</strong> polaronuli gamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturulidreifuli Zvradobiskvanturi Teoriis ageba naxevargamtarebsa<strong>da</strong> ionur kristalebSi <strong>da</strong>fuZnebuli kubos wrfivi gamo-Zaxilisa <strong>da</strong> SeSfoTebis Teoriaze. ga<strong>da</strong>tanis meqanikuri (kinetikuri)koeficientebis (eleqtrogamtaroba, Zvradoba) gamoTvlakvanturi disipaciuri sistemebis zemoTmiTiTebuli modelebisTvis.ZiriTadi Sedegebi <strong>da</strong> mecnieruli siaxlewarmodgenil sadisertacio naSromSi ga<strong>da</strong>wyvetilia Semdegiamocanebi:− mowesrigebul operatorTa formalizmisa <strong>da</strong> T-namravlTateqnikis <strong>da</strong>xmarebiT, sawyisi korelaciebis Sesustebis principisa<strong>da</strong> Sfm-is gamoyenebis gareSe, gamoyvanilia <strong>da</strong> gamokvleulia axali,zusti, ganzogadoebuli kvanturi evoluciuri (kinetikuri)gantolebebi gamoricxuli bozonuri (fononuri) amplitudebiTdrois ormomentiani wonasworuli korelaciuri <strong>da</strong> grinis funqciebisTvisdinamiuri qvesistemisTvis, romelic urTierTqmedebsbozonur TermostatTan. aseTive saxis kvanturi kinetikuri gantolebebikorelaciuri funqciebisaTvis miRebulia liuvilissuperoperatoruli formalizmisa <strong>da</strong> proeqciuli operatorismeTodis <strong>da</strong>xmarebiT.− dinamiuri qvesistemis bozonur (fononur) TermostatTanurTierTqmedebis hamiltonianis mixedviT, SeSfoTebis Teoriismeore miaxloebaSi miRebulia axali, ganzogadoebuli kvanturikinetikuri gantolebebi gamoricxuli bozonuri amplitudebiT,xix


qvesistemis drois ormomentiani wonasworuli korelaciuri funqciebisTvis– rogorc markoviseuli, ise aramarkoviseuli formiT– romelTa <strong>da</strong>jaxebiTi integralebi Seicaven cxa<strong>da</strong>d gamoyofilsawyisi korelaciebis evoluciur wevrebs.− kubos wrfivi reaqciisa <strong>da</strong> SeSfoTebis Teoriis farglebSi,naxevargamtarebisa <strong>da</strong> ionuri kristalebisTvis agebulia eleqtronuli<strong>da</strong> polaronuli <strong>da</strong>balsixSiruli gamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturulidreifuli Zvradobis Tanmimdevruli, koreqtulikvanturi Teoria, <strong>da</strong>fuZnebuli kvanturi disipaciuri sistemebiszemoTmiTiTebuli modelebisTvis ganzogadoebul kvanturkinetikur gantolebebze korelaciuri funqciebisaTvis “deni-denze”eleqtronisa <strong>da</strong> polaronisaTvis, romlebic urTierTqmedebenfononebTan Sfm-is gamoyenebis gareSe.− miRebulia <strong>da</strong> gamokvleulia analizuri gamosaxulebebieleqtronisa <strong>da</strong> polaronis relaqsaciuri maxasiaTeblebisTvis(impulsis relaqsaciis sixSire <strong>da</strong> sxv.); gamoTvlilia wonasworulikorelaciuri funqciebis – “deni-denze” – milevis dekrementebi.napovnia eleqtrogamtarobis tenzoris analizuri saxeeleqtron-fononuri sistemisTvis kristalis <strong>da</strong>bali temperaturebisa<strong>da</strong> <strong>da</strong>balsixSiruli gareSe eleqtruli velebis Sem-TxvevaSi <strong>da</strong> gamoTvlilia ga<strong>da</strong>tanis meqanikuri koeficientebi(Zvradoba, eleqtrogamtaroba) kvanturi disipaciuri sistemebis3aRniSnuli modelebisTvis; napovnia agreTve “2K BΤhω -problemis”nawilobrivi ga<strong>da</strong>wyveta frolixis polaronis <strong>da</strong>baltemperaturuliZvradobis TeoriaSi.− miRebulia temperaturuli Sesworebebi eleqtronisa <strong>da</strong> polaronisdreiful Zvradobebze, romlebic ganpirobebulia sawyisikorelaciebis evoluciuri wevrebis arsebobiT kvantur kinetikurgantolebebSi wonasworuli korelaciuri funqciebisTvis“siCqare-siCqareze” (“impulsi-impulsze”) eleqtronisa <strong>da</strong> polaronisTvis.<strong>da</strong>dgenilia, rom es Sesworebebi warmoadgenen mcire0xx


sidideebs Sesrulebuli miaxloebebisa <strong>da</strong> ganxiluli TeoriisfarglebSi.sadisertacio naSromis praqtikuli mniSvneloba:naSromSi <strong>da</strong>smuli amocanebis ga<strong>da</strong>wyvetam moiTxova arawonasworulistatistikuri meqanikis zogierTi meTodis SemdgomiganviTareba. miRebuli zusti, ganzogadoebuli kvanturievoluciuri gantolebebi wonasworuli korelaciuri funqciebisTvisSesaZlebelia gamoyenebuli iqnas ga<strong>da</strong>tanis movlenebisgansaxilvelad <strong>da</strong> gamosakvlevad - kubos wrfivi reaqciis TeoriisfarglebSi, sawyisi korelaciebis Sesustebis principisa <strong>da</strong>Sfm-is <strong>da</strong>Svebebis gareSe - myari sxeulebis <strong>da</strong> kondensirebulgaremoTa fizikis dinamiur qvesistemaTa sxva modelTaTvis(kvanturi disipaciuri sistemebisTvis), romlebic urTierTqmedebenbozonur velTan (TermostatTan). (mag. brounis kvanturi nawilakismoZraobis Sesaswavlad, romelic ganixileba rogorcwrfivi, milevadi harmoniuli oscilatori, <strong>da</strong> romlis dinamikaaRiwereba kaldeira-legetis mikroskopuli modeluri hamiltonianiT).naSromSi ganviTarebuli formalizmi, meTodebi <strong>da</strong> miRebulikinetikuri gantolebebi martivad SesaZlebelia ganvrcobiliiqnas kinetikuri movlenebis Sesaswavlad <strong>da</strong> ga<strong>da</strong>tanis meqanikurikoeficientebis (mag. Zvradoba, eleqtrogamtaroba) gamosa-Tvlelad: <strong>eleqtronebis</strong> urTierTqmedebisas (gabnevisas) arapolaruloptikur fononebze, piezoeleqtrul fononebze, agreTvesxva didi radiusis mqone polaronis modelTaTvis (mag. akustikuripolaronis modelisTvis - eleqtronis fononebTan ZlieriurTierTqmedebis SemTxvevaSi). gamoyvanili ganzogadoebuli kvanturikinetikuri gantolebebi korelaciuri funqciebisTvis kvanturidinamiuri qvesistemisTvis, romelic urTierTqmedebs fononurvelTan, SesaZlebelia gamoyenebul iqnas normaluri (arazegamtari)metalebis eleqtrowinaRobis gamosaTvlelad <strong>eleqtronebis</strong>gabnevisas akustikur fononebze. naSromSi warmodgeniliformalizmis <strong>da</strong>xmarebiT SesaZlebelia temperaturuli Seswore-xxi


ebis povna metalTa eleqtrowinaRobisTvis (Sesworebebi bloxgrunaizenisformulaSi), romlebic agreTve ganpirobebulia<strong>eleqtronebis</strong> fononebTan urTierTqmedebisas sawyisi korelaciebisgaTvaliswinebiT.sadisertacio naSromSi miRebuli ZiriTadi Teoriuli Sedegebispraqtikuli mniSvneloba (Rirebuleba) ganisazRvrebaagreTve imiT, rom ukanasknel wlebSi samecniero literaturaSigamoqveyn<strong>da</strong> mravali Teoriuli naSromi, romelic Seexeba bozonurvelTan (TermostatTan) urTierTqmedebaSi myofi kvanturidinamiuri sistemis kinetikis sakiTxebs, sa<strong>da</strong>c ganixileba msgavsiformalizmi <strong>da</strong> meTodebi, romelic ganviTarebulia avtoris mierwarmodgenil naSromSi.xxii


Tavi I. dinamiuri sistemebi, romlebic urTierTqmedebenTermostatTan (bozonur velTan)ukanaskneli aTwleulebis ganmavlobaSi arsebiTad gaizar<strong>da</strong> interesiim dinamiuri sistemebis SeswavlaSi, romlebic urTierTqmedebaSiimyofebian TermostatTan (bozonur velTan) [1]. amasTan erTad didi yuradRebaeTmobo<strong>da</strong> im procesebis detalur Seswavlas, romlebic mimdinareobdnenim mcire sistemebSi, romlebic urTierTqmedebdnen rogorcsustad, agreTve Zlierad Termodinamikur wonasworobaSi myof didiTavisuflebis xarisxis mqone sistemasTan – TermostatTan. ZiriTadi me-Todi, romlis saSualebiTac xdebo<strong>da</strong> am procesebis gamokvleva eyrdnobo<strong>da</strong>midgomebs, romlebic ganviTarebuli iyo arawonasworul statistikurmeqanikaSi <strong>da</strong> stohastikuri (SemTxveviTi) procesebis TeoriaSi [1-2].ukanasknel periodSi, mkacri midgomebis ganviTarebam arawonasworulstatistikur meqanikaSi SesaZlebeli gaxa<strong>da</strong> Camoyalibebuliyo sakmaodsruli <strong>da</strong> mkacri maTematikuri Teoria arawonasworuli modelurisistemebisa [3]. Ria arawonasworuli modeluri sistemebis (Ria sistemawarmoadgens mcire qvesistemas, romelic urTierTqmedebs TermostatTan)srulyofili maTematikuri Teoriis Seqmna warmoadgens Se<strong>da</strong>rebiT ufromartiv <strong>da</strong> perspeqtiul problemas (amocanas) arawonasworuli statistikurimeqanikisa [3-4].arawonasworuli statistikuri meqanikis <strong>da</strong> fizikuri kinetikis problemaTafarTo wre <strong>da</strong>kavSirebulia im modeluri hamiltonianebis SeswavlasTan,rodesac dinamiuri qvesistema s urTierTqmedebs S TermostatTan,romelic aRiwereba bozonuri veliT; Tanac, rogorc wesi, ur-TierTqmedeba aiReba wrfivi Termostatis (boze) operatorebis (amplitudebis)mixedviT. zogad SemTxvevaSi, mTliani (s+S) sistemis hamiltonianiSesaZlebelia warmovadginoT Semdegi saxiT:Hts (, , Σ ) =Γ (, ts) + H + H () t(1.1)sa<strong>da</strong>c: Γ (,) ts aris s qvesistemis sakuTari hamiltoniani;H Σ- Termostatis (bozonuri velis) hamiltoniania, xoloΣHintwarmoadgens urTierTqmedebis hamiltonians s qvesistemisa STermostatTan.int23


saxe:s qvesistemis urTierTqmedebisas bozonur velTanH int-s aqvs Semdegi+ +Hint () t = ∑ ⎡⎣Ck(, tsb )k+ Ck(,)tsb ⎤k ⎦. (1.2)koperatorebi, romlebic figurireben (1.1) <strong>da</strong> (1.2) gamosaxulebebSiarian Cveulebriv Sredingeriseul warmodgenaSi Cawerili dinamiuricvladebi. b k<strong>da</strong> b +kwarmoadgenen Termostatis boze amplitudebs – gaqrobisa<strong>da</strong> <strong>da</strong>badebis operatorebs Cawerils meoradi <strong>da</strong>kvantvis warmodgenaSi.bozonur velTan urTierTqmedebis SemTxvevaSi: H = +Σ ∑ h ω( kbb ) warmoadgensk kbozonuri velis sakuTar hamiltonians. k – aris im kvanturi ricxvebis er-Toblioba, romlebic aRweren s qvesistemis urTierTqmedebas STermostatTan <strong>da</strong> TviT Termostatis mdgomareobas. un<strong>da</strong> aRiniSnos, rom sdinamiuri qvesistemis operatorebis cxadi saxe arsad ar konkretdeba.gamokvlevaTa Zalian didi raodenoba miZRvnilia kinetikur movlenebisadmi<strong>da</strong> procesebisadmi, romlebic mimdinareoben kvantur dinamiursistemebSi, romlebic urTierTqmedeben TermostatTan (bozonur velTan) <strong>da</strong>aRiwerebian (1.1-1.2) hamiltonianiT [1-21].ganvixiloT axla Tanamedrove fizikis TvalsazrisiT zogierTi aqtualuri<strong>da</strong> mniSvnelovani magaliTebi, romlebic farTo Seswavlis saganigax<strong>da</strong> statistikuri fizikis, myari sxeulebisa <strong>da</strong> kondensirebul garemoTafizikis, gamosxivebis Teoriis <strong>da</strong> sxv. - kvanturi dinamiuri sistemebisa,romlebic urTierTqmedeben TermostatTan.k24


1.1. kvanturi disipaciuri <strong>da</strong> Ria arawonasworuli modeluri sistemebi(zogierTi magaliTi)1.1.1. fermionuli sistemaqvesistema s warmoadgens araurTierTqmed fermionTa sistemas,romlebic xasiaTdebian fermi amplitudebiT <strong>da</strong> adgili aqvs SemdegTanafardobebs:eΓ (,) ts = Λ ( f) a a ; C (, ts)= L a aεt+ +∑ f f k k∑f + k f( f ) V ( f )eeC ts L aa L a aVVεtεt+ * + * +k(, ) =k∑f f + k=k∑f −k f,( f ) ( f )(1.3)sa<strong>da</strong>c L k, L * kwarmoadgenen “C-sidideebs”. vinai<strong>da</strong>n fermionebs gaaCniaT spini,(1.3) gamosaxulebebSi f ( f,σ )≡ r <strong>da</strong> f r miekuTvneba kvazidiskretul speqtrs(σ - warmoadgens spinis aRmniSvnel maCvenebels). simbolo ( f k)rogorc ( f + k) ≡ ( f + k,σ )rr+ waikiTxeba; SesaZlebelia agreTve ganxiluli iqnas SemTxveva,rodesac fermionebi urTierTqmedeben erTmaneTTan. maSin Γ (,) ts hamiltonianSigaTvaliswinebuli un<strong>da</strong> iqnas agreTve <strong>da</strong>matebiTi wevrebi,romlebic aRweren fermionebs Soris urTierTqmedebas <strong>da</strong> maT urTierTqmedebasgareSe velebTan. un<strong>da</strong> aRiniSnos, rom aseTi saxis dinamiurisistemebis ganxilvamde mivyavarT amocanebs, romlebic moiTxoven metalTaeleqtrogamtarobis gansazRvras, zegamtarobis movlenis axsnas <strong>da</strong> sxv. [14-15].1.1.2. Txevadi metalis an Senadnobis modelimravalkomponentiani Txevadi metalis an Senadnobis hamiltonianiSesaZlebelia CavweroT Semdegi saxiT [9]:MH ts , H : H C tsδρ ,( ) ( )=Γ + =∑∑ r rintintl=1klklkNl+ −1−ikRlj( , ) =,( , ) : δρ = δlk l −k lk l ∑rrr r r − rko ,j=1C ts C ts N eδρ= δρ*rrlk l,− k.(1.4)aq s warmoadgens eleqtronuli sistemis maCvenebels, Γ (,) ts aris eleqtronulisistemis sakuTari hamiltoniani, romelic zogad SemTxvevaSi Seicavs25


eleqtron-eleqtronuli urTierTqmedebis wevrebsac; Hintwarmoadgenseleqtronul <strong>da</strong> ionur sistemebs Soris urTierTqmedebis hamiltonians, laris ionuri sistemis maCvenebeli, 1≤l ≤M ; M M- komponentebis ricxvia; R ljwarmoadgens l-uri komponentis j-uri ionis koordinatas;δρ r aris l-urilkkomponentis koleqtiuri koordinati, xolo N laris l-uri komponentis ion-Ta ricxvi: ajamva k rsimboloTi xorcieldeba kvazidiskretuli speqtrismixedviT. V-ki warmoadgens sistemis moculobas. magaliTad,araurTierTqmedi <strong>eleqtronebis</strong> modelisTvis, romlebic imyofebian gareSereleqtronul velSi Et () <strong>da</strong>ZabulobiT, erTeleqtronian hamiltonians aqvsSemdegi saxe:rrH =Τ p −eE() t ⋅ r+ V r : V r = r −R,M Nr r r lr( ) ( ) ( ) ∑∑υl ( lj )l= 1 j=1sa<strong>da</strong>c: e - eleqtruli muxtia, Τ( p)- warmoadgens energias (magaliTad,r2r pΤ ( p)= , m - efeqturi masaa), rr <strong>da</strong>2m impulsi. V ( r )( r Rlj)p aris eleqtronis koordinati <strong>da</strong>– eleqtronis ionebTan urTierTqmedebis potencialia, xoloυ − rwarmoadgens eleqtronis urTierTqmedebis psevdopotencials l-urilkomponentis j-ur ionTan. am SemTxvevaSi Cven gveqneba:r rr r Γ ts , = ε p −eE() t ⋅ r;ε p =Τ p + V r( ) ( ) ( ) ( ) ( )Mr r r r−ikrV r = Cυ% (0); υ%( k) = n dre υ ( r)( )∑l=1l l l lNC C r r nMl*l= : ∑ l= 1; υl ( ) = υl( ); =Nl=1(,) = r r rrikrC ts e Cυ % ( k).lkTxevadi metalis an Senadnobis modelSi, romelic aRiwereba (1.4)hamiltonianiT, ionuri sistema ganixileba rogorc klasikuri <strong>da</strong> aRiwerebakoleqtiuri cvladiTll∫NVδρ r . Txevadi metalis modelisaTvis ionuri sistemislkkonfiguraciebis mixedviT gasaSualoeba <strong>da</strong>fuZnebulia f { ρ rek}% koleqtiuricvladebiT gausis ganawilebis funqciiT gasaSualoebaze, romlisTvisacsamarTliania Semdegi formula:26


Maq% ≡ ∏∏df%lk ({ lk})⎧⎫⎧1MM*exp⎨∑α rδρ r⎬ = exp ⎨ ∑∑α rα r δρ r ⋅δρr .lk lk , −% ⎬r l k mk lk mk f⎩ i= 1 ⎭ % ⎩2fem , = 1 k⎭r r∫ rl=1 k... δρ δρ ...; sa<strong>da</strong>c α r warmoadgens l<strong>da</strong> k r -s nebismierffunqcias <strong>da</strong> adgili aqvs Semdeg Tanafardobebs:* 1 1rrr−ikrδρ r ⋅ δρ r = s ( ) = ⎡1 + ( ( ) −1 ) ⎤.%llk Cnlk lk f⎣l ∫ dre gllrCN CN⎦ll* 1 n rrr−ikrδρ r ⋅ δρ r = s ( ) = ∫ ( () −1 ) : ≠ ,lk mk f%lmk dr glmr e l mN Nsa<strong>da</strong>c g () r warmoadgenen radialuri ganawilebis funqciebs:lmlk( )g () r = g R −R,lm lm li mjlmxolo s ( k ) sidideebi warmoadgenen ionuri sistemis struqturul faqtorebs:s ( k) = s ( k ), s * ( k) = s ( k ). struqturuli faqtorebi iZlevian srullmmllmlminformacias Txevadi metalis an Senadnobis ionuri sistemis Sesaxeb,romlebic aiReba eqsperimentuli monacemebi<strong>da</strong>n. un<strong>da</strong> aRiniSnos, rommodelis sruli formulirebisaTvis aucilebelia ionebis⎫R ljSemTxveviTikoordinatebis ganawilebis funqciis miTiTeba, romlis mixedviTac xdebagasaSualoeba. Txevadi metalis an Senadnobis aRniSnuli modeli xSiradgamoiyeneba metalebis, Senadnobebisa <strong>da</strong> ga<strong>da</strong>civebuli “metaluri minebis”kvantur eleqtronul TeoriaSi, romlebic <strong>da</strong>fuZnebulia am nivTierebaTaatomur <strong>da</strong> struqturul Taviseburebebze [9].1.1.3. nawilaki, romelic urTierTqmedebs garemosTanam modelSi ganixileba qvesistema s (gamoyofili nawilaki), romelicurTierTqmedebaSi imyofeba sxva nawilakebisagan Sedgenil garemosTan.aseTi sistemis hamiltonians aqvs saxe:r r2 N 2Ρ ΡiH = + ∑ + U( r1, r2, r3,... rN).2m2Mi=1iaq: m <strong>da</strong> p r warmoadgens masasa <strong>da</strong> impulss gamoyofili nawilakisa; Mi<strong>da</strong>Ρ riarian masebi <strong>da</strong> impulsebi garemos nawilakebisa. r i– garemos nawilakTaradius-veqtorebia, U warmoadgens mTeli sistemis nawilakTa ur-27


TierTqmedebis potenciur energias, xolo r r – gamoyofili nawilakisradius-veqtoria.sa<strong>da</strong>c:sawyisi hamiltoniani SesaZlebelia warmovadginoT Semdegi formiT:( ) int,H =Γ s + H + HΣr2rrΡr r rΓ ≡s= + −1 22mrN 2ΡiHΣ= ∑ + U( r0, r1, r2...rN)2MU∇( s) H ( e 1 ) U ( r, r, r...r )i=1irrU∇( ) ⎡r r r r r r r r( N) ( N)Hint = e −1 0, 1, 2... −0, 1, 2... ⎤⎣U r r r r U r r r r .Σ ⎦hamiltonianis aseTi saxiT warmodgenisas igulisxmeba, rom gansaxilvelgamoyofil nawilaks gaaCnia wonasworuli mdebareoba radiusveqtoriTr 0raRac saSualo velSi, romelic ganpirobebulia garemosnawilakebTan urTierTqmedebiT <strong>da</strong> U - potencialuri energia gaSliliausasrulo mwkrivad nawilakis r u wanacvlebis mixedviT wonasworulir r rmdebareobi<strong>da</strong>n: =0+rrr r r r r rr r u; ( , , ... ) U ∇U r r r r e U( r , r , r ... r )1 2 N= rr0 1 2rNΣN(1.5)(∇ r - warmoadgensgradientis operators gamoyofili nawilakis koordinatebis mixedviT).amrigad, gamoyofili nawilaki, romelic imyofeba saSualo velSi ( Hhamiltoniani), ganicdis am saSualo velis fluqtuaciebis zemoqmedebas( Hinthamiltoniani). simbolo ... (1.5) formulaSi aRniSnavs gasaSualoebasgaremos mdgomareobaTa mixedviT. Tu gavSliT u r wanacvlebas normaluri* +koordinatebis mixedviT: u r = ∑α r a +rχ χαχaχ<strong>da</strong> gamoviyenebT formulas:rr∇ ≈ ∇=rrU* +e u ∑( χaχ χaχ)χχr r r= α + α ∇ (rac Seesabameba nawilakis mxolod wrfivisurTierTqmedebis gaTvaliswinebas garemosTan, romelic aRiwerebaHint-hamiltonianiT), <strong>da</strong> <strong>da</strong>viyvanT diagonalur saxezeHshamiltonianis imnawils, romelic kvadratulia r u wanacvlebis mixedviT, maSin SesaZlebelia(1.5) hamiltoniani warmovadginoT (1.1) formiT. simboloebi χ aRniSnavsgamoyofil oscilatorebs, xolo a χ<strong>da</strong> a χ+warmoadgenen gaqrobisa <strong>da</strong><strong>da</strong>badebis operatorebs χ oscilatorebisa. amrigad s qvesistemis rolSigveqneba oscilatorebis erToblioba hamiltonianiTHs= ∑ ω aa+ , sa<strong>da</strong>cχχ χ χ28


ωχaris χ oscilatoris sixSire. Tu gavSliT U( 0, 1, 2... N ) potenciurr r renergias wanacvlebebis - u1, u2,...uNmixedviT mwkrivad, maSin garemoshamiltoniani H ΣSesaZlebelia warmovadginoT agreTve rogorcoscilatorebis erToblioba (rasakvirvelia, am SemTxvevaSic un<strong>da</strong>gamoviyenoT Sesabamisi miaxloebebi). garemos nawilakTa radius-rveqtorebisTvis gveqneba: r1 = ri0 + ui( i=1,2,... N ), sa<strong>da</strong>c, r i0-warmoadgensgaremos nawilakTa wonasworuli mdebareobebis Sesabamis radius-veqtorebs.samecniero literaturaSi xSirad ganixileba magaliTi kvanturi oscilatorisa,romelic urTierTqmedebs TermostatTan (bozonur velTan) [6].aseTi sistemis hamiltonianisTvis gvaqvs gamosaxuleba:( , )sa<strong>da</strong>c:+ * * +k k k( ) Σ intH =Γ ts , + H + H ,+*+hω0aa + h[f ( t)a + f ( t ]; H = +Σ ∑ h ω ( kbb ) k k;k? ( t,s)= ) a+ +∑ ⎡k( ) k k ( ) ⎤k( )Hint = ⎣C tsb , + C tsb , ⎦;k+C ts , = hλa + h υ a;k k kC ts = hλa+D υ a <strong>da</strong> kvanturi harmoniuli oscilatori imyofeba gareSe,cvladi klasikuri Zalis moqmedebis qveS, romelic wrfiva<strong>da</strong>a<strong>da</strong>kavSirebuli (urTierTqmedebs) TermostatTan – araurTierTqmedi kvanturioscilatorebis sistemasTan. aa , , b , b+ +k karian gaqrobis <strong>da</strong> <strong>da</strong>badebisbozeoperatorebi,λ , λ , υ , υ warmoadgenen urTierTqmedebis mudmivebs,* *k k k kromlebic proporciuli arian1Vsididisa, sa<strong>da</strong>c: V - sistemis moculobaa,r k talRuri veqtoria, romelic iRebs kvazidiskretul mniSvnelobebs,f () t aris cvladi klasikuri gareSe Zala, xoloω , 0ωk– oscilatorebissixSireebia.aseTi saxis dinamiur sistemebs vxvdebiT zogierTi amocanebis ganxilvisaskvanturi radiofiziki<strong>da</strong>n, myari sxeulebisa <strong>da</strong> kondensirebulgaremoTa fiziki<strong>da</strong>n <strong>da</strong> sxv. magaliTebis saxiT SesaZlebelia moviyvanoTsistemebi, romlebic Sedgebian atomebisa <strong>da</strong> molekulebisagan <strong>da</strong> imyofebianlazeris talRis velSi myar sxeulebSi an airebSi, romlebic TamaSobenTermostatis rols [7-8, 10-12].29


1.1.4. eleqtron-minarevuli sistemaes modeli warmoadgens sistemas, romelic Sedgeba <strong>eleqtronebis</strong>agan,romlebic urTierTqmedeben garemoSi SemTxveviT ganlagebul minarevulircentrebTan <strong>da</strong> gareSe eleqtrul velTan, romlis <strong>da</strong>Zabulobaa - Et (). aseTisaxis modeli aRiwereba Semdegi hamiltonianiT:rH =Γ ( ts , ) + Hint; Γ ( ts , ) = Hs−eE( t)⋅r;r2NΠNΠΡ(1.6)H = ; H = ≡int ∑ϕ∑ϕ( r−r),s e l2ml= 1 l=1r rsa<strong>da</strong>c: e, m, , p Sesabamisad warmoadgenen eleqtronis muxts, masas, radiusveqtors<strong>da</strong> impulss. ϕ ( r − r l ) aris eleqtronis urTierTqmedebis energiaminarevul centrTan, romelic imyofeba wertilSi, romlis radius-veqtoriarl, xolo N Π– minarevuli centrebis ricxvia. xSirad ganixilaven ufrozogad models eleqtron-minarevuli sistemisa, romlis hamiltonianiCaiwereba Semdegi saxiT [22]:sa<strong>da</strong>c: Hint = Hie+ HeΣ;H( ) int,H =Γ s + H + H + H(1.7)eΣee= 1 0 i, j=1 i jΣNr2 2 Npie 1= ∑ + ∑ r r warmoadgens N <strong>eleqtronebis</strong>2m 8πε−hamiltonians, romlebic urTierTqmedeben erTmaneTTan kulonuri ZaliT, r i<strong>da</strong> p riaris i-uri eleqtronis koordinata <strong>da</strong> impulsi masaTa centrismimarT <strong>da</strong> Γ ( s), Hie,HeΣmoicema Semdegi formulebiT:r2Ρ rrr rr−iqRaΓ ( s) = − NER;Hie= ∑U( q)e2Nmrqa ,rHΣ= ( , ) ΦrreM q λq,λρq.∑rq,λ(1.8)(1.8) formulebSi H ie<strong>da</strong>H eΣ- eleqtronis urTierTqmedebis hamiltonianebiaminarevTan <strong>da</strong> fononur velTan; Γ ( s)warmoadgens eleqtronulisistemis masaTa centris hamiltonians (Ρ r <strong>da</strong> R r – masaTa centris impulsi<strong>da</strong> koordinataa Sesabamisad), xoloρNiqriq= ∑ er aris <strong>eleqtronebis</strong>i=1+simkvrivis operatoris furie saxe (warmodgena); Φ rq, λ= b rq, λ+b r− q,λfononuri+velis operatoria; br q, λ,b r−q,λ- fononebis gaqrobis <strong>da</strong> <strong>da</strong>badebisoperatorebia talRuri veqtoriT q r , λ warmoadgens fononuri speqtris30


Stos, M( q,λ )- eleqtron-fononuri urTierTqmedebis matriculi elementebia,U( q r ) - minarevTa potencialis furie saxea, ε 0- dieleqtrikuliSeRwevadobaa, xoloR ra- a-uri minarevuli centris koordinatia. (1.7) <strong>da</strong>(1.8) formulebi faqtiurad warmoadgenen N-urTierTqmedi <strong>eleqtronebis</strong>a <strong>da</strong>N Π- SemTxveviT ganlagebuli minarevuli centrebis modelur hamiltonians,romlebic imyofebian E r<strong>da</strong>Zabulobis mqone gareSe eleqtrul velSi <strong>da</strong>urTierTqmedeben TermostatTan, romelic aRiwereba fononuri (bozonuri)velis H ΣhamiltonianiT.modeluri hamiltonianebi (1.6)–(1.8) xSirad gamoiyeneba mouwesrigebelisistemebis speqtraluri <strong>da</strong> kinetikuri maxasiaTeblebis Seswavlisas <strong>da</strong>gamokvlevisas. zemoTmiTiTebuli hamiltonianebis SeswavlaSi mivyavarTeleqtronuli ga<strong>da</strong>tanis movlenebis Teoriismraval amocanas (rogorcwrfivs, aseve arawrfivs) myar sxeulebSi; zogierT sakiTxs susti <strong>da</strong>Zlieri lokalizaciis Teoriisa, mouwesrigebeli sistemebis eleqtrogamtarobisTeoriis sxva<strong>da</strong>sxva amocanebs <strong>da</strong> sxv. [22-23].1.1.5. dikes modelebi gamosxivebis TeoriaSiam sistemebSi umartivesi modeluri hamiltoniani aRwers qvesistemisurTierTqmedebas fotonebTan (fotonur velTan). urTierTqmedebishamiltoniani aiReba wrfivi fotonebis (boze) operatorebis mixedviT. ammodelis farglebSi ganixileba N raodenobis ori energetikuli donismqone (ordoniani) gamomsxiveblebi, romelTa sixSirea O. uSveben, romgamomsxiveblebi urTierTqmedeben erTmaneTTan mxolod velis saSualebiT.rogorc cnobilia, aseTi saxis hamiltoniani pirvelad SemoRebuli iyoatomTa spontanuri koherentuli gamosxivebis movlenis aRsawerad.Tu ugulvebelvyofT kinetikur efeqtebs, romlebic ganpirobebuliagamomsxivebelTa moZraobiT, gacvliTi <strong>da</strong> eleqtrostatikuri urTierTqmedebebiT<strong>da</strong> aRvwerT gamomsxivebelTa dipolur urTierTqmedebaseleqromagnitur velTan “mbrunavi talRis” miaxloebaSi, maSin miviRebTmodels, romelic aRiwereba hamiltonianiT [10-11]:31


( Σ ) =Γ ( ) + + ( Σ )H t,, s s H H ts , , ,zsa<strong>da</strong>c: ( ) hΣh ( )Γ s = Ω S H r r=∑ kbbΣint: +0rk kkεtεte− + e * +Hint ( ts , , Σ ) = gSb r r r + gSb r r r∑rk k k ∑rk k kVVkω (1.9)<strong>da</strong> gamomsxivebeli sistemis spinuri operatorebi S, <strong>da</strong>kavSirebulia paulismatricebTan stan<strong>da</strong>rtuli TanafardobebiT:kS± ±= ∑ ±r rikrjkSjej;Szkz= ∑ S e±jjr rikr j;± x y ( x,y,z)1 ( x,y,z)j= SjiS ; Sj= σjS ±aq: r jaris j -uri gamomsxiveblis radius-veqtori, brk<strong>da</strong>2b + r - warmoa-kdgenen fotonebis gaqrobis <strong>da</strong> <strong>da</strong>badebis boze operatorebs (amplitudebs)talRuri veqtoriT k r , urTierTqmedebis (bmis) mudmivag r <strong>da</strong>kavSirebuliakd±ga<strong>da</strong>svlis denis <strong>da</strong>debiT-sixSiriani operatoris furie-komponentasTanSemdegi TanafardobiT:( k )32πh ω r rr = r±⋅ rk k dr( )g d e eυsa<strong>da</strong>c: υ warmoadgens nivTierebis kuTr moculobas, h - plankis mudmivaa,xolo ω ( kr ) – fotonis sixSirea. aq: Σ Termostatis rols TamaSobsfotonuri veli, romelSic “moTavsebulia” gamomsxivebelTa ssistema.calke aRebuli, erTeulovani urTierTqmedebis aqtis Sedegad, romelicxorcieldeba eleqtromagnitur velsa <strong>da</strong> gamomsxivebels Soris, adgiliaqvs fotonuri velis kvantis gamosxivebas (STanTqmas), ris gamocgamomsxivebeli ga<strong>da</strong>dis ori SesaZlo energetikul mdgomareobi<strong>da</strong>n erTerTSi.un<strong>da</strong> aRiniSnos, rom mocemuli modelisTvis SesaZlebelia agreTvesxva midgoma, romlis drosac Termostatis rols TamaSobs gamomsxivebelTasistema, xolo dinamiuri qvesistemis saxiT gvevlineba bozonuriveli [10]. sakiTxi Termostatisa <strong>da</strong> dinamiuri sistemis SerCevis Sesaxebwydeba imis<strong>da</strong> mixedviT, Tu rogori procesebi ganixileba. ase magaliTad,midgoma romelic ganxilulia [7]-Si Seesabameba eleqtromagnituri velisrelaqsaciis procesebis Seswavlas rezonatorSi, xolo midgoma, romelicgaSuqebulia [8]-Si aRwers Tavisufal sivrceSi gamosxivebisas spinuri sis-32


temis relaqsaciis procesebs, romlis drosac sivrce ganixilebaTermostatis rolSi. xSirad ganixilaven dikes iseT modelebs, romlebicaRiwerebian ufro zogadi hamiltonianiT <strong>da</strong> romlebic Seicaven agreTveordoniani obieqtebis kinetikuri energiis operators [ix. mag. [11,24]].Seswavlili iyo agreTve dikes modelebi, rodesac dinamiuri qvesistema s(gamosxiveba) urTierTqmedeb<strong>da</strong> erTdroulad S atomur <strong>da</strong> S 1 fononursistemebTan [12].aqve un<strong>da</strong> aRiniSnos, rom aseTi tipis dinamiur sistemebamde (dikesmodelebamde) mivyavarT mravali problemis ganxilvas kvanturi radiofiziki<strong>da</strong>n<strong>da</strong> lazeruli gamosxivebis fiziki<strong>da</strong>n, zegamosxivebis Teorii<strong>da</strong>n<strong>da</strong> sxv. amitom dikes tipis modeluri sistemebis Seswavla <strong>da</strong>gamokvleva, rogorc Ria arawonasworuli kvanturi dinamiuri sistemebisa,warmoadgens did samecniero interess. cxadia, rom dikes modelebisaRmweri hamiltonianebi miekuTvnebian (1.1) <strong>da</strong> (1.2) formulebiT gamoxatulhamiltonianTa klass.1.1.6. eleqtronebi magnetikSi, romlebic urTierTqmedeben kristalis magniturqvesistemasTanaseTi saxis dinamiur sistemebSi ganixileba <strong>eleqtronebis</strong> urTier-Tqmedeba magnetikis atomTa spinebTan S-d modelis farglebSi [25-26]. er-Tzonian miaxloebaSi sistemis hamiltonians aqvs Semdegi saxe:aqH = He+ HM+ HAH = Ea a ; Hr2ArrRnα= a SS σσ ' a e(1.10)∑∑r ri( χ−χ')( ) '+ +r r r r re χ χσ χσ A χσ e nα χσrNr rχσχ, χ'σσ , 'He– gamtarobis <strong>eleqtronebis</strong> hamiltoniania,H A- warmoadgens hamiltonians,romelic aRwers <strong>eleqtronebis</strong> urTierTqmedebas magnetikis lokalizebulspinebTan (A – spin-eleqtronuli urTierTqmedebis mudmiva, N –magnitur atomTa ricxvia, S rre- zonuri eleqtronis spinis operatoria, S nα-warmoadgens magnituri atomis spinis operators, romelic moTavsebuliarkvanZSi, romlis radius-veqtoria ; n - kvanZis nomeria, α - qvemesrisnomeri).RnαHM– magnituri qvesistemis hamiltoniania (Cveulebriv, rogorcwesi iReben haizenbergis gacvliTi urTierTqmedebis hamiltonians33


lokalizebuli spinebisaTvis).H A– hamiltonianSi eleqtronis spinissaSualo spinebTan urTierTqmedebis gancalkevebis Semdeg, (1.10)hamiltoniani SesaZlebelia Caiweros Semdegi saxiT:H = H0+ H1+HMr rH Ea a a S a S er2Ar ri − R0= ∑ + ∑n αχ χσ χσ χσ e χσ ' ' αrN r rσσ 'χσχ, χ'σσ , ', nα+ +( χ χ')sa<strong>da</strong>c: r r r( )rr r rH a S a S S er r( χ χ')( )re ( n )r2A+i − R1= r∑' '−n αχσ χσ α αN r rσσ 'χχ , 'σσ , ', nαSnα(1.11)Tu CavatarebT kanonikur gar<strong>da</strong>qmnas <strong>da</strong> ga<strong>da</strong>valTa + r χσ,a r χσoperatorebi<strong>da</strong>naxalC + g,Cgoperatorebze kristalis mocemuli gansazRvrulimagnituri struqturis dros, maSin SesaZlebelia H 0hamiltonianis <strong>da</strong>yvanadiagonalur saxeze (magaliTad: feromagnetiki-ormesriani antiferomagnetiki<strong>da</strong> a.S.). magnituri mowesrigebisas magnituri struqturiswarmoqmnas mivyavarT eleqtronuli zonis gaxleCamde or zonad (qvezonad)[26], ise rom axali C ( + )g<strong>da</strong> C geleqtronuli operatorebi xasiaTdebian kvanturiricxvebis erTobliobiT: g r = ( χσυ r , , ) <strong>da</strong> energetikuli speqtriT εg<strong>eleqtronebis</strong>Tvis (υ warmoadgens qvezonis nomers). magaliTad, aseTSemTxvevas aqvs adgili calRerZa helikoi<strong>da</strong>luri struqturebisSemTxvevaSi, romelTa kerZo SemTxvevas warmoadgenen feromagnetiki <strong>da</strong>antiferomagnetiki). holstein-primakovis gar<strong>da</strong>qmnis gamoyenebiTSesaZlebelia Srn,αspinuri operatorebi<strong>da</strong>n ga<strong>da</strong>videT spinuri talRebisoperatorebze <strong>da</strong> miviRoT hamiltoniani, romelic aRwers <strong>eleqtronebis</strong>urTierTqmedebas magnonebTan <strong>da</strong> romelic zoga<strong>da</strong>d Seicavs mravalmagnonian(erTmagnoniani, ormagnoniani <strong>da</strong> a.S.) wevrebs. (holstein-primakovisgar<strong>da</strong>qmnis samarTlianoba SesaZlebelia martivad <strong>da</strong>vasabuToTmagnetikebisaTvis, romlebic imyofebian mowesrigebul fazaSi Zalian<strong>da</strong>bali temperaturebis dros: Τ> 1). zogierT SemTxvevebSi, rogorc wesi, SesaZlebeliaSemovisazRvroT mxolod wrfivi operatoruli wevrebiT magnonebis34


mixedviT. aseT SemTxvevebSi (1.10)-(1.11) hamiltonianebi erTmagnonianiprocesebisaTvis miiReben Semdeg saxes:sa<strong>da</strong>c:∑H = H + H + H( )sΣ+ + +int ⎣ k k k k ⎦ k ggk , ' g g'kN gg , 'int+ +H = ε g C C ; H = h Ω dd(1.12)s g g Σk k kgk1H = ⎡B () sd + B () sd ⎤; B () s = A CC ,∑Ωk- k magnonuri modis sixSirea; k ( k,j)∑∑( )= r , j - magnonuri Stos nomeria,d , d + - magnonebis gaqrobis <strong>da</strong> <strong>da</strong>badebis boze operatorebia, xolokkAgg'kwarmoadgens “C-sidides”.magaliTad, antiferomagnetikebSi, sa<strong>da</strong>c <strong>eleqtronebis</strong> energetikulidoneebi ga<strong>da</strong>gvarebulia spinis mixedviT, SesaZlebelia SemovisazRvroTerTmagnoniani procesebis ganxilviT <strong>da</strong>bali temperaturebis dros.(ormagnoniani procesebi, romlebic aRiwereba H1wevriT (1.11) hamiltonianSi,romelic SeicavsSznαzα− S wevrebs, warmoadgenen mcire sidideebs,rodesac 2 S >> 1 <strong>da</strong> temperatura aris <strong>da</strong>bali.( S − Sr


eleqtron-fononur sistemaze <strong>da</strong> didi radiusis mqone polaronis modelebze.1.2. eleqtron-fononuri sistema. eleqtronis urTierTqmedeba akustikur <strong>da</strong>polarul optikur fononebTankristalur myar sxeulebSi, magaliTad farTozonian naxevargamtarebSi,eleqtronis fizikuri Tvisebebi, romelic ga<strong>da</strong>adgildeba kristalSi,ZiriTa<strong>da</strong>d ganisazRvreba perioduli potencialiT, romelsac qmniankristaluri mesris kvanZebSi ganlagebuli ionebi.ionTa rxevebs wonasworuli mdebareobebis maxloblobaSi mivyavarT<strong>eleqtronebis</strong> energiebis praqtikulad myisier cvlilebamde <strong>da</strong>kristalisaTvis Sredingeris adiabaturi gantolebis hamiltonianSi, romelicaRwers <strong>eleqtronebis</strong> mdgomareobebs, <strong>da</strong>matebiTi wevris -Hint-iswarmoqmnamde. es <strong>da</strong>matebiTi wevri aRwers <strong>eleqtronebis</strong> urTierTqmedebasfononebTan. ionebis mcire amplitudebiT rxevebisSemTxvevaSi, fononuri(bozonuri) sistema Σ warmoadgens araurTierTqmedi harmoniuli oscilatorebiserTobliobas. am sistemis energias aqvs Semdegi saxe:kH = +Σ ∑h ω ( kbb ) k k, <strong>da</strong> igi warmoadgens fononuri velis sakuTriv hamiltoniansmeoradi <strong>da</strong>kvantvis warmodgenaSi (nulovani rxevebimxedvelobaSi ar miiReba). rac Seexeba urTierTqmedebis energias –H int– igiwrfivad aris <strong>da</strong>mokidebuli calkeuli, aRebuli harmoniuli oscilatorisnormalur koordinatebze.im sistemis Tvisebebis Seswavla, romelic Sedgeba kvazinawilakisagan(eleqtronisagan) <strong>da</strong> fononuri (bozonuri) velisagan, romelTa SorisurTierTqmedeba aris wrfivi fononuri operatorebis mixedviT, warmoadgensmyari sxeulebis <strong>da</strong> kondensirebul garemoTa fizikis <strong>da</strong> agreTve veliskvanturi Teoriis metad mniSvnelovan amocanas.amgvarad, eleqtron-fononuri sistema warmoadgens magaliTs eleqtronisurTierTqmedebisa <strong>da</strong>kvantul fononur velTan kristalSi. am SemTxvevaSiqvesistema S Sedgeba erTi kvazinawilakisagan (eleqtronisagan),xolo Σ Termostatis rolSi gvevlineba fononuri veli.cnobili gamartivebebis Semdeg, ararelativisturi kvazinawilaki(eleqtroni), romelic urTierTqmedebs kristaluri mesris rxevebis <strong>da</strong>kva-36


ntul skalarul velTan, aRiwereba frolix-pekaris tipis hamiltonianiT[29-31]:r2Ρ r+ ikr * − ikr +H = + ∑ ω ( kbb ) + Ve b Ve bk k ∑⎡r r+r rh r r r r r ⎤rr k k k k2m⎣⎦kkrω > 0,( k )sa<strong>da</strong>c r – eleqtronis radius-veqtoria, Ρ r - kvaziimpulsis operatori, br,b + r(1.13)- fononebis gaqrobis <strong>da</strong> <strong>da</strong>badebis operatorebia talRuri veqtoriT k r , m- eleqtronis efeqturi masaa kristaluri mesris periodul potencialurvelSi, xolo ω ( kr ) – warmoadgens fononuri velis kvantis sixSires,romelic aris k r -talRuri veqtoris radialurad simetriuli funqcia:r rω − k = ω k .( ) ( )kk1.2.1. eleqtronis urTierTqmedeba kristaluri mesris akustikur rxevebTan.deformaciis potencialis meTodirogorc cnobilia, <strong>eleqtronebis</strong> gabnevisas akustikur fononebzegrZeltalRovan miaxloebaSi ka «1 (a - mesris mudmivaa) fononebis dispersiismiaxloebiT kanons aqvs Semdegi saxe [32-33]: ω ( k) = Vsk , sa<strong>da</strong>c V sr r–bgeris siCqarea kristalSi, xolo (1.13) formulis Vrk– mudmivebi, romlebicwarmoadgenen eleqtronis fononebTan urTierTqmedebis energiis furie-komponentebs,moicemian Semdegi TanafardobiT:Vrk⎛4πα⎞= ⎜V ⎟⎝ ⎠12 2h 1 2km,(1.14)sa<strong>da</strong>c: V – kristalis moculobaa, xoloα=Dm2 238πρhVs– warmoadgenseleqtron-fononuri urTierTqmedebis uganzomilebo mudmivas; D aris deformaciispotencialis mudmiva <strong>da</strong> ρ - kristalis masuri simkvrive. un<strong>da</strong>aRiniSnos, rom zemoTmoyvanili gamosaxulebebi samarTlianiaIII VA B <strong>da</strong>II VIA B naxevargamtarebisaTvis, romelTaTvisac adgili aqvs dispersiisizotropul kanons <strong>da</strong> romlebSic zonis eqstremumi imyofeba brilueniszonis centrSi.37


mokled SevexoT deformaciis potencialis meTods. am meTodis ideamdgomareobs SemdegSi: rodesac kristalSi vrceldeba drekadi talRaelementaruli ujredi ganicdis deformacias, icvleba misi moculoba(icvleba kristaluri mesris mudmiva), rac Tavis mxriv iwvevs gamtarobiszonis fskerisa <strong>da</strong> savalento zonis Weris mdebareobis cvlilebas, vinai<strong>da</strong>nzonis sigane mgrZnobiarea mesris mudmivas sididis cvlilebis mimarT. gamtarobiszonis fskeris cvlileba ki faqtiurad warmoadgens gamtarobiseleqtronis urTierTqmedebis energias kristaluri mesris rxevebTan.akustikuri rxevebis SemTxvevaSi, rodesac k r→ 0 yvela atomi elementarulr rujredSi irxeva sinfazurad. rogorc cnobilia, r wertilis U( r)wanacvleba kristalSi grZeltalRovan miaxloebaSi (ka «1) SesaZlebeliaCavweroT Semdegi saxiT [32]:r rsa<strong>da</strong>c er( k)kjr 3rrr 1 r rrrikr + −ikr( ) = r ⎡ r∑+ rr kj jk jkN ⎣k, j=1U r e ( k) b e b e ⎤av⎦,(1.15)aris polarizaciis veqtori, romlis absoluturi mniSvnelobaakustikuri rxevebisaTvis grZeltalRovan miaxloebaSi erTis tolia, xoloNN – elementarul ujredTa raodenobaa kristalSi.vinai<strong>da</strong>n grZeltalRovan miaxloebaSi akustikuri rxevebisas irxevamxolod elementaruli ujredis masaTa centri <strong>da</strong> TviT ujredi ki arganicdis deformacias, amitom urTierTqmedebis energia warmoadgensr rmxolod U ( av ) wanacvlebis koordinatebis mixedviT pirveli warmoebulebiswrfiv funqcias <strong>da</strong> ar aris <strong>da</strong>mokidebuli TviT wanacvlebissidideze. amitom urTierTqmedebis energia Caiwereba Semdegi saxiT:r rH = DdivUint ( ).(1.16)avHintsidides uwodeben deformaciis potencials, xolo D proporciulobiskoeficients deformaciis potencialis mudmivas, romelicZiriTa<strong>da</strong>d ganisazRvreba eqsperimenti<strong>da</strong>n. (1.15) <strong>da</strong> (1.16) formulebis<strong>da</strong>xmarebiT martivad miviRebT:3iD rrrr rrrikr + −ikrHint= ( ker ( k)) ⎡br ∑e −b re⎤.kj jk jkN⎣⎦rk, j=1(1.17)ukanaskneli formuli<strong>da</strong>n Cans, rom im SemTxvevaSi, rodesac gvaqvsizotropuli gabneva gamtarobis eleqtroni urTierTqmedebs mxolod grZiv38


grZeltalRovan akustikur fononebTan ( k // er ( k )) . zogad SemTxvevaSi,rodesac gabneva anizotropulia <strong>da</strong> deformaciis potencialis mudmivakjwarmoadgens tenzorul sidides D αβ. ( αβ= , 1,2,3)- deformaciis potencialisTvisgveqneba gamosaxuleba:3int=∑( ) ( )j=1H DαβU, sa<strong>da</strong>c ( j)αβU αβwarmoadgensdeformaciis tenzors. am SemTxvevaSi urTierTqmedebis procesSimonawileobas Rebuloben agreTve ganivi fononebic [32-33].1.2.2. eleqtronis urTierTqmedeba polarul optikur fononebTanpolarul nivTierebebSi (polarul naxevargamtarebsa <strong>da</strong> ionur kristalebSi)ionTa rxevebisas warmoiqmneba ara marto deformaciis potenciali,aramed gar<strong>da</strong> amisa, adgili aqvs Sorsmqmedi makroskopulieleqtruli velis warmoSobas <strong>da</strong> amitom eleqtronis urTierTqmedebas amvelTan mivyavarT <strong>da</strong>matebiTi gabnevis meqanizmis warmoSobamde. esurTierTqmedeba, romelsac uwodeben eleqtronis gabnevas polarul optikurfononebze, bevr kristalebSi ufro arsebiTia, vidre denis (muxtis)ga<strong>da</strong>mtanis gabneva akustikur fononebze. am saxis gabnevac grZeltalRovanmiaxloebaSi aRiwereba (1.13) saxis hamiltonianiT. Vr – sidideebskeleqtronis gabnevisas polarul optikur fononebze aqvs Semdegi saxe [29-31]:r12rhω( k) ⎛4πα⎞⎛2 mω( k)⎞Vr=− i ;k r 12 ⎜ ⎟ U =⎜ ⎟12k U ⎝ V ⎠ ⎝ h ⎠21⎛1 1 ⎞ eUα = ⎜ − ⎟ r .2 ⎝ε∞ε0⎠hω( k)12(1.18)aq V aris sistemis (kristalis) moculoba, e <strong>da</strong> m – eleqtronis muxti<strong>da</strong> efeqturi masaa, Sesabamisad; α - eleqtron-fononuri urTierTqmedebisfrolixis uganzomilebo bmis mudmivaa, xolo ε 0<strong>da</strong> ε ∞- warmoadgenenmocemuli nivTierebis statikuri <strong>da</strong> optikuri dieleqtrikuliSeRwevadobis mudmivebs. eleqtronis urTierTqmedebisas grZiv optikurrfononebTan: max ω( k)≡ ω0- warmoadgens dispersiis armqone, kristalisgrZivi optikuri rxevebis sixSires. zogierT SemTxvevaSi, eleqtron-39


fononurisistemisTvis:Hsr2p=2m gamosaxulebis nacvlad aucilebeliagamoyenebuli iqnas ufro zogadi saxe eleqtronis energiisa gamtarobiszoni<strong>da</strong>n- H =Τ( p r ). iseve rogorc (1.2) formulaSi, ajamva k r -talRurisveqtoriT (1.13). formulaSi xorcieldeba kvazidiskretuli speqtrismixedviT:r ⎛2π 2π 2π⎞k = ⎜ h h h ⎟ L = V⎝ L L L ⎠31, 2, 3; ,(1.19)sa<strong>da</strong>c h 1, h 2, h 3– mTeli ricxvebia (rogorc <strong>da</strong>debiTi, aseve uaryofiTi).amrigad, eleqtron-fononuri sistemisaTvis (1.1), (1.2), (1.13) formulebis+Tanaxmad, Ck()s <strong>da</strong> Ck() soperatorebs aqvs Semdegi saxe:ikrC () s = Ve r ;kkr rrr+ * −ikrk()=kC s Ve(simbolo * aRniSnavs kompleqsurad SeuRlebuls).(1.20)rodesac eleqtron-fononuri sistema imyofeba gareSe, erTgvarovanreleqtrul velSi, romlis <strong>da</strong>Zabuloba Et (), maSin eleqtronis gareSeeleqtrul velTan urTierTqmedebis hamiltonians aqvs saxe:Hsext=−eE r r(). tr(1.21)im SemTxvevaSi, rodesac gareSe eleqtruli veli icvleba harmoniulikanoniT eleqtruli velis <strong>da</strong>ZabulobisTvis gvaqvs:r −() =r εEt Ee t0cos( ω t),(1.22)sa<strong>da</strong>c: ω warmoadgens cvladi eleqtruli velis sixSires, xolo E r0- arisvelisamplitu<strong>da</strong>,te −εTanamamravli aRwers gareSe urTierTqmedebis+adiabatur CarTvas (gamorTvas), rodesac t →m ∞ <strong>da</strong> ε → 0( ε > 0) .eleqtronis polarul optikur fononebze gabnevisas, eleqtronfononuriurTierTqmedebis (ufro zoga<strong>da</strong>d polaronis amocanis) specifikamdgomareobs imaSi, rom saerTod, uganzomilebo parametri α , romelicaRwers eleqtron-fononuri urTierTqmedebis siZlieres, ar SeiZlebaCaiTvalos rogorc mcire sidide. III-V jgufis naxevargamtarebSi eleqtronfononuriurTierTqmedeba SesaZlebelia iyos susti ( α < 1); II-VI jgufispolarul naxevargamtarebsa <strong>da</strong> dieleqtrikebSi saSualo siZlieris ( α ≈ 1)<strong>da</strong> ionur kristalebSi Zlieri ( α >> 1). amitom, zogad SemTxvevaSi,uaryofili un<strong>da</strong> iqnas <strong>da</strong>Sveba imis Sesaxeb, rom muxtis ga<strong>da</strong>mtanTa40


(<strong>eleqtronebis</strong>) energetikuli speqtri ganisazRvreba maTi sustiurTierTqmedebiT idealuri kristaluri mesris potencialur velTan <strong>da</strong>kristaluri mesris rxevebis roli mdgomareobs imaSi, rom maT mivyavarTSe<strong>da</strong>rebiT iSviaT ga<strong>da</strong>svlebTan eleqtronis mdgomareobebs Soris idealurkristalSi. polarul kristalebSi eleqtron-fononuri urTierTqmedeba iwvevseleqtronuli speqtris arsebiT cvlilebas (polaronuli efeqti),denis ga<strong>da</strong>mtanebis Se<strong>da</strong>rebiT Zlier gabnevas optikur fononebze <strong>da</strong> amukanasknelTa dispersiis kanonis cvlilebas. yvelaferi es ki arTulebspolaruli kristalebis eleqtruli <strong>da</strong> agreTve optikuri TvisebebisSeswavlas [29-31, 36-39].amrigad, Zlieri (arasusti) eleqtron-fononuri urTierTqmedebisSemTxvevaSi, zoga<strong>da</strong>d eleqtron-fononuri sistemis Termodinamikis sakiTxebisganxilvisas <strong>da</strong> kinetikuri movlenebis Seswavlisas Cven bunebrivad<strong>da</strong>vdivarT polaronis amocanis ganxilvamde [29-30, 37-39].1.3. polaronis amocana. didi radiusis mqonepolaronis modelebiukanasknel wlebSi aqtualuri gax<strong>da</strong> sakiTxi struqturuladSedgenili nawilakebis dinamiuri modelebis agebisa. warmodgenebi nawilakisrTuli struqturisa <strong>da</strong> am nawilakis agznebuli mdgomareobebisarsebobis Sesaxeb yovelTvis warmoadgen<strong>da</strong> Zlieri urTierTqmedebis (bmis)Teoriis ZiriTad sakiTxs. un<strong>da</strong> aRiniSnos rom Zlieri bmis TeoriebissiZneleebi Tavi<strong>da</strong>nve ganpirobebuli iyo iseTi cnebebis SemoRebasa <strong>da</strong>operirebasTan, romlebic arsebiTad gansxvavebodnen Tavisufali velebisTeoriis warmodgenebisagan. n.n. bogolubovis SromebSi ganxiluli <strong>da</strong>gamokvleuli iyo amocana ararelativisturi nawilakis urTierTqmedebisa<strong>da</strong>kvantul skalarul velTan adiabaturi miaxloebis zRvrul SemTxvevaSi[35,40].41


1.3.1. polaronis frolixisa <strong>da</strong> pekaris modelebipirvelad amocana ararelativisturi nawilakis urTierTqmedebisa<strong>da</strong>kvantul skalarul velTan <strong>da</strong>smuli iyo frolixis mier egreTwodebulipolaronebis problemis gamosakvlevad. polaronebis problema mdgomareobsgamtarobis <strong>eleqtronebis</strong> yofaqcevis SeswavlaSi polarul kristalebSi.eleqtroni, romelic imyofeba kristalSi, Tavisi kulonuri veliT waanacvlebsionebs TavianTi wonasworuli mdebareobebi<strong>da</strong>n; Tavis mxriv warmoqmniliionuri polarizacia moqmedebs eleqtronze <strong>da</strong> iwvevs misi energiisSemcirebas. kristalSi ga<strong>da</strong>adgilebisas, eleqtrons Tan ga<strong>da</strong>aqvskristaluri mesris <strong>da</strong>maxinjebis are. eleqtroni <strong>da</strong> masTan erTad aRebuliTviTSeTanxmebuli polarizaciuli veli SesaZlebelia ganxiluli iqnesrogorc kvazinawilaki, romelsac uwodeben polarons [29,38]. un<strong>da</strong>aRiniSnos, rom TviT polaronis koncepcia SemoRebuli iqna pekaris mier,romelic ganixilav<strong>da</strong> zRvrul SemTxvevas eleqtronisa <strong>da</strong> kristalurimesris rxevebis Zlieri urTierTqmedebisa <strong>da</strong> mis aRsawerad iyeneb<strong>da</strong>adiabatur miaxloebas, romelic warmoadgens naxevradklasikur meTods [29-30].istoriulad pirveli <strong>da</strong> yvelaze gavrcelebuli midgoma polaronuliamocanis amoxsnisaTvis <strong>da</strong>fuZnebuli iyo or ZiriTad miaxloebaze,romlebic arsebiTad gansazRvraven polaronuli mdgomareobebis Tvisebebs:1) efeqturi masis miaxloeba, romlis Tanaxma<strong>da</strong>c eleqtronisurTierTqmedeba xisti kristaluri mesris periodul potencialTangaTvaliswinebulia m efeqturi masiT, rogorc parametriT. aseT SemTxvevaSieleqtronis kinetikuri energia Τ ( p)= gamtarobis zonaSi <strong>da</strong> TviTr2r Ρ2mzonis sigane formalurad warmoadgenen SemousazRvrel sidideebs <strong>da</strong>amitom ar TamaSoben parametrebis rols polaronis amocanisaTvis; 2)kontinualuri miaxloeba, romlis drosac ar gaiTvaliswineba kristalurimesris diskretuli struqtura. am miaxloebaTa CarCoebSi, polaronisamocana warmoadgens velis kvanturi Teoriis tipiur magaliTs ferminawilakisurTierTqmedebisa <strong>da</strong>kvantul fononur velTan, <strong>da</strong> amitom,rogorc aseTi, igi gax<strong>da</strong> erT-erTi magaliTi velis Teoriis meTodebisgamoyenebisa myari sxeulebis fizikaSi.42


polaronis ZiriTadi mdgomareobis Tvisebebis Seswavla arsebiTadmartivdeba susti <strong>da</strong> Zlieri eleqtron-fononuri urTierTqmedebis zRvrulSemTxvevebSi. susti eleqtron-fononuri urTierTqmedebis SemTxvevaSipolaronis fizikuri maxasiaTeblebi kargad aRiwereba CveulebriviSeSfoTebis Teoriis gamoyenebiT, xolo Zlieri eleqtron-fononuriurTierTqmedebis SemTxvevaSi polaronuli mdgomareoba aRiwerebaTviTSeTanxmebuli midgomiT, romelic pirvelad ganxiluli iyo pekarismier <strong>da</strong> romelic eyrdnobo<strong>da</strong> adiabatur miaxloebas [30-31, 39].velis Teoriis lagranJiseuli formulirebisa <strong>da</strong> stan<strong>da</strong>rtuli <strong>da</strong>kvantvisproceduris gamoyenebiT, frolixisa <strong>da</strong> pekaris mier miRebuli <strong>da</strong>ganxiluli iyo polaronuli sistemis hamiltoniani (1.13-1.18) saxiT. vinai<strong>da</strong>nSredingeris gantolebis zusti amoxsna (1.13) saxis hamiltonianiT ver iqnanapovni, amitom sxva<strong>da</strong>sxva dros mravali avtoris mier gamoyenebuli iyomiaxloebiTi meTodebi, romlebsac susti eleqtron-fononuriurTierTqmedebis SemTxvevaSi mivyavarT an stan<strong>da</strong>rtuli tipis SeSfoTebisTeoriasTan, an sxva<strong>da</strong>sxva saxis variaciul midgomebTan, romlebicfaqtiurad warmoadgenen hartri-fokis miaxloebis ama Tu im modifikacias[30, 37-38]. am gamokvlevebis Sedegebi gviCvenebs, rom uZravi eleqtronisenergia mcirdeba sididiT: ∆ E =−hωα, 0romelic SesaZlebelia ganxiluliqnas, rogorc polaronis sakuTari energia. gar<strong>da</strong> amisa icvlebaeleqtronis efeqturi masa:* −1m = m(1−α 6) .susti eleqtron-fononuri urTierTqmedebis SemTxvevaSi polaronipirvel miaxloebaSi SesaZlebelia warmovidginoT rogorc kvazinawilaki(eleqtroni), romelic garemoculia fononuri velis arakorelirebulikvantebis RrubliT, romelTa saSualo ricxvi proporciulia bmismudmivasi (polaronis frolixis modeli) [29].fizikis TvalsazrisiT bevrad ufro saintereso <strong>da</strong> aqtualuria ZlierurTierTqmedebis SemTxveva nawilakisa fononur velTan. Zlier eleqtronfononururTierTqmedebas mivyavarT fononuri vakumis polarizaciaze, raciwvevs sabolood Sedgenili kvazinawilakis struqturis Camoyalibebas.cxadia, rom nebismier gamoTvliT sqemas(algoriTms) un<strong>da</strong> Seswevdes unari am Camoyalibebuli struqturismodelirebisa ukve pirvel miaxloebaSi [38-40].43


pekaris Tanaxmad, Zlieri eleqtron-fononuri urTierTqmedebisSemTxvevaSi, kristaluri mesris deformacias, romelic gamowveuliagamtarobis eleqtroniT, mivyavarT efeqturi potencialuri ormosCamoyalibebamde <strong>da</strong> eleqtronis CaWeramde diskretul energetikul doneze,romelsac Seesabameba ukanasknelis finituri moZraoba. GaerTianebulisistema (eleqtroni plus deformaciis are), rogorc mTliani ga<strong>da</strong>adgilebakristalSi efeqturi masiT, romelic sagrZnoblad aRemateba eleqtronismasas (efeqturs) gamtarobis zonaSi [30,37,39].amgvarad, Zlieri eleqtron-fononuri urTierTqmedebis SemTxvevaSipekaris mier ganviTarebuli Teoria iTvaliswinebs ionuri kristalisdieleqtrikul polarizacias gamowveuls gamtarobis eleqtroniseleqtruli veliT. warmoqmnili lokaluri polarizacia <strong>da</strong>kavSirebuliaionTa wanacvlebasTan <strong>da</strong> amitom is aris inerciuli; mas ar SeuZlia “mxariaubas” Se<strong>da</strong>rebiT ufro swrafad moZrav eleqtrons <strong>da</strong> amitom es lokaluriinerciuli polarizacia, rogorc ukve iTqva, eleqtronisTvis qmnispotencialur ormos. sakmarisad Rrma ormoSi xdeba eleqtronisavtolokalizacia <strong>da</strong> am warmoqmnili potencialuri ormos siRrmesakmarisia, raTa masSi arsebobdes diskretuli energetikuli doneebieleqtronisTvis. kristalTa didi umravlesobisTvis ormos siRrme 0,5-1eleqtron-voltis rigisaa. eleqtroni, romelic imyofebaavtolokalizebul mdgomareobaSi erT-erT aseT energetikul donezeTavisi eleqtruli veliT “iWers” kristaluri mesris lokalurpolarizacias. ionebi TavianTi inerciulobis gamo “aRiqvamen” eleqtronisara myisier, aramed saSualo eleqtrul vels. eleqtronis aseTiavtolokalizebuli mdgomareoba anu kristalis aseTi mdgomareobebipolarizaciuli potencialuri ormoTi, romelSiac lokalize-buliaeleqtroni, iwodeba polaronul mdgomareobebad (polaronis pekarismodeli) [30,39-40].erT-erT mniSvnelovan <strong>da</strong> ZiriTad parametrs, romelic axasiaTebspolaronul mdgomareobas, warmoadgens polaronis radiusi, romelicaRwers maxasiaTebel zomebs kristaluri garemos deformaciis arisa. Tueleqtron-fononuri urTierTqmedeba aris susti, maSin polaronis radiusiSesaZlebelia Sefasebuli iqnas ganusazRvrelobis Tanafardobi<strong>da</strong>n:12 12r ≈ h Ρ( mω0) , rogorc maxasiaTebeli zoma eleqtronis fluqtuaciebisa44


sivrceSi, romelic ganpirobebulia virtualuri fononebis gamosxivebisa<strong>da</strong> STanTqmis procesebiT. Zlieri eleqtron-fononuri urTierTqmedebisSemTxvevaSi polaronis radiusis sidide arsebiTa<strong>da</strong>a <strong>da</strong>mokidebuli amurTierTqmedebis xasiaTze. frolix-pekaris polaronis modelSi, rodesacα >>1, martivi Tvisobrivi Sefaseba polaronis radiusisaTvis iZlevaSemdeg mniSvnelobas:12 12r ≈ h Ρ( mω0) α , rac Seesabameba polaronis radiusisSemcirebas bmis mudmivas zr<strong>da</strong>sTan erTad [37,41].didi radiusis mqone polaronis adiabatur TeoriaSi polaronis zomaganisazRvreba optimaluri balansis pirobi<strong>da</strong>n gamomdinare eleqtroniskinetikuri energiis <strong>da</strong>debiTi wvlilisa, romelic lokalizebuliaSemosazRvruli sivrceSi, <strong>da</strong>debiTi wvlilisa deformirebuli kristalurimesris energiisa <strong>da</strong> uaryofiTi wvlilisa eleqtron-fononuriurTierTqmedebis energiisa. yvela es wvlili erTi <strong>da</strong> igive rigisaasididis mixedviT, rac jamSi iZleva mogebas polaronis energiisaTvis,Se<strong>da</strong>rebiT Tavisufali eleqtronis mdgomareobisaTvis aradeformirebulikristaluri mesrisaTvis (polaronuli wanacvleba) [37,42-43]. un<strong>da</strong>aRiniSnos, rom principSi polaronuli mdgomareobebis Tvisebebi arsebiTadganisazRvreba sami masStaburi energetikuli parametriT: D, hω , E , sa<strong>da</strong>cE Ρwarmoadgens polaronul wanacvlebas – energiis Semcirebas eleqtronfononurisistemisaTvis polarizaciuli saxis urTierTqmedebis gamo <strong>da</strong>warmoadgens im energetikul masStabs, romelic axasiaTebs amurTierTqmedebis intensivobas. D aris <strong>eleqtronebis</strong> ga<strong>da</strong>unomrvi zonissigane, xolo ω warmoadgens fononebis maxasiaTebel rxevebis saSualo six-Sires. didi radiusis mqone polaronis piroba moicema Semdegi TanafardobiT:rΡ >a, sa<strong>da</strong>c a aris kristaluri mesris mudmiva. SesaZlebelianaCveneb iqnas, rom didi radiusis mqone polaronisaTvis adgili aqvsutolobas: E D< 1, romelic faqtiurad ekvivalenturia zemoT moyvaniliutolobisa [37,41].Ρpolaronuli mdgomareobebis mdgradobisTvis aucilebelia, romeleqtronis bmis energia potencialur ormoSi aRematebodes ionTa siTburimoZraobis saSualo energias kristalSi. variaciuli meTodis <strong>da</strong>xmarebiTpekarma ganaviTara mkacri Teoria eleqtronis Zlieri urTierTqmedebisaΡ45


izotropul ionur dieleqtrikTan, rodesac kristali ganixilebo<strong>da</strong>rogorc uwyveti garemo.pekaris Tanaxmad eleqtronis energia polarizebul kristalSi(dieleqtrikSi), romlis polarizaciis veqtoria - Ρ r r( ) ,warmoidginebaSemdegi saxiT [29-30] (nulovan adiabatur miaxloebaSi, rodesac argaiTvaliswineba ionTa moZraobis kinetikuri energia).r2r r* * 2h r r r r r r rΕ⎡⎣Ψ, Ρ ⎤⎦=− Ψ ( ) ∆Ψ ( ) + 2 Ρ ( ) − Ρ( ) ( ) ,2∫ r rdr πε ∫ rdr ∫ rDrdr(1.23)mr rr r 2 1−rsa<strong>da</strong>c: Dr ( ) = e∫Ψ( 1)r r dr3 1warmoadgens eleqtruli velis induqciis−1veqtors dieleqtrikis wertilSi, romlis radius-veqtoria r r , xolo*1 − −1 −1ε = ε∞− ε 0aris polarizebuli garemos efeqturi dieleqtrikuliSeRwevadoba (ix. (1.18) formula). (1.23) formulis pirveli ori wevri aRwerseleqtronisa <strong>da</strong> polarizaciuli velis energiebs, xolo ukanaskneli wevri- maT Soris urTierTqmedebis energias. (1.23) gamosaxuleba ganixilebarogorc funqcionali – Ψ( r ) <strong>da</strong> Ρ r r( ) funqciebis mimarT. rodesac kristaliimyofeba ZiriTad mdgomareobaSi, maSin am funqcionals un<strong>da</strong> gaaCndesabsoluturi minimumi, Ψ( r ) <strong>da</strong> Ρ r r( ) funqciebis <strong>da</strong>moukidebeli variaciebisdros, im pirobiT rom adgili eqneba talRuri funqciis normirebisSenaxvis pirobas:∫r 2 rΨ ( ) dr = 1.(1.24)Tu gavutolebT nuls (1.23) funqcionalis variacias, romelic ganpirobebuliaΡ r r( ) polarizaciis cvlilebiT, rodesac Ψ( r ) talRurifunqcia fiqsirebulia, maSin martivad <strong>da</strong>vadgenT kavSirs Ρ r r( )sidideebs Soris:r r 1 rΡ ( ) = Dr ( ),*4πε<strong>da</strong> Dr ( r )(1.25)sa<strong>da</strong>c: Dr ( r ) - induqcia (1.23) formulis Tanaxmad ganisazRvreba Ψ( r1)talRuri funqciis saSualebiT. (1.25) gamosaxulebis <strong>da</strong>xmarebiT, martivadvpoulobT (1.23) funqcionalis saxes, romelic <strong>da</strong>mokidebulia mxolod Ψ( r )talRur funqciaze:22 1 2I[ Ψ ] = h ( ) dr D ( rdr ) .*2m∫ ∇Ψ r r −8πε∫ r r r(1.26)46


IΨ [ ] funqcionali gansazRvravs polarizebuli kristalis (dieleqtrikis)energias, romlisTvisac polarizacia SeTanxmebulia eleqtronismdgomareobasTan, romelic aRiwereba Ψ( r )-funqciiT.polarizebulikristalis aseTi mdgomareobisaTvis, eleqtronisTvis ufro “xelsayrelia”energetikuli TvalsazrisiT imyofebodes ara gamtarobis zonaSi, aramedmdgomareobaSi, romelic Seesabameba eleqtronis moZraobas kristalisSemosazRvrul (finitur) areSi <strong>da</strong> romelic ganisazRvreba - Ψ( r ) talRurifunqciiT. eleqtronisTvis es energetikulad ufro xelsayreli mdgomareobaSesaZlebelia ganisazRvros (1.26) funqcionalis minimumispirobi<strong>da</strong>n, (1.24) Tanafardobis gaTvaliswinebiT, Ψ( r ) funqciis mixedviT.(1.26) funqcionalis minimizaciisaTvis pekarma gamoiyena pir<strong>da</strong>pirivariaciuli meTodi [29-30]. ZiriTadi mdgomareobis (polaronulimdgomareobis) funqciis - Ψ ( r r) =Ψ0( ) . aproqsimacia xdebo<strong>da</strong> ramodenimeparametris saSualebiT. am funqcias hqon<strong>da</strong> Semdegi saxe:r2 −α′rΨ () = A[1+ α′r + βr] e0(1.27)sa<strong>da</strong>c: A mudmiva ganisazRvrebo<strong>da</strong> normirebis pirobi<strong>da</strong>n (talRurifunqciisTvis) <strong>da</strong> igi toli iyo sididis:A232α=π γ γ2( 14+ 168 + 720 );1β1− x2 2γ = ; Ψ ( ) (1 ) ;4α′2 0x = A + x + γ x e x = 2α ′ γ , (1.28)2sa<strong>da</strong>c x warmoadgen<strong>da</strong> uganzomilebo cvlads. variaciuli gaTvlebi α′ <strong>da</strong>2meγ parametrebisaTvis iZleo<strong>da</strong> Semdeg mniSvnelobebs: α′ = 0 ,6585 ,,2 *h εγ = 0,1129; (1.28) formulebis <strong>da</strong>xmarebiT polaronis ZiriTadi mdgomareobisenergiisaTvis miRebuli iyo Semdegi gamosaxuleba [30]:2 2 2 2 43 πhA2 π eAΕ0( αγ , ) = ( 1+ 4γ + 24γ ) −* 5( 10,494+ 209,88γ+2 mαεα+ + +2 3 41884γ 8507,8γ 16727 γ .)(1.29)Se<strong>da</strong>rebiT ufro uxeSi gaTvlebisTvis, pekaris mier gamoyenebuli iyoagreTve talRuri funqcia, romelic Seicav<strong>da</strong> erT variaciul parametrs.saerTod polaronis ZiriTadi mdgomareobis energia ar iyo Zalian“mgZnobiare” SerCeuli variaciuli parametrebis raodenobis mimarT.47


magaliTad, erTi <strong>da</strong>moukidebeli meore parametris <strong>da</strong>mateba talRurfunqciaSi saSualebas iZleo<strong>da</strong> ZiriTadi mdgomareobis energiis mxolod2%-iT Semcirebas. erTi variaciuli parametris mqone normirebul talRurfunqcias hqon<strong>da</strong> Semdegi saxe:r α 'Ψ = +7π32− ' r0( r) ( 1 α ' r)e α ,(1.30)sa<strong>da</strong>c21 meα ' ≡ = , α′ parametris (1.30) mniSvneloba ganisazRvrebo<strong>da</strong> (1.23),2 *r 2 h ε0(1.26) <strong>da</strong> (1.30) formulebis <strong>da</strong>xmarebiT – (1.26) funqcionalis minimumispirobi<strong>da</strong>n. TviT (1.30) talRur funqcias Seesabamebo<strong>da</strong> (1.26) funqcionalisSemdegi mniSvneloba:meIΨ [ ] =− ≡− ⋅ hhε4200,054 20,054 ωα*20,(1.31)sa<strong>da</strong>c: α - aris eleqtron-fononuri urTierTqmedebis frolixisuganzomilebo mudmiva (ix. (1.18) formula). (1.31) gamosaxuleba faqtiuradgansazRvravs polarizebuli kristalis srul energias. (1.23) <strong>da</strong> (1.25)gamosaxulebebis <strong>da</strong>xmarebiT SesaZlebelia ganisazRvros kristalispolarizacia, romelic Seesabameba (1.30) mdgomareobas.rr rr e r 21−rΡ0( ) = Ψ0( 1) dr3 1,x4πε∫ r r (1.32)−rdivΡ0( r)rxolo (1.32) formulisa <strong>da</strong> V0()r =−∫dr1r−r'1Tanafardobis <strong>da</strong>xmarebiTvipoviT sferuli polarizaciuli potencialuri ormos formas (saxes),romelSiac moZraobs eleqtroni (ix. nax.1). eleqtronis talRuri funqcia(ix. 1.28) napovni α′ variaciuli parametris saSualebiT Caiwereba SemdegisaxiT:( )Ψ = + + ⋅32 2 2() r 0,1229α 1 αr 0,4516 α r e −αr.0TviT V 0() r potencials aqvs Semdegi analizuri saxe:22αe ⎡1 −x⎛ 120() =− − + 0,7605+ 0,2605 + 0,05087 +*V r e x xε⎢x⎜⎣ ⎝ x3 4+ 0,005703x+ 0,0003024 x ) ⎤⎦,(1.33)sa<strong>da</strong>c, x ganisazRvreba (1.28) formuliT. rodesac x >> 1, maSin eqsponencialuriTanamamravli aris Zalian mcire <strong>da</strong> V 0() r potencialis saxe aris48


2ekulonuri: V0( r)→ − ; ( r >>1); xolo r = 0 wertilSi potencials gaaCnia*ε rparaboluri tipis minimumi. polaronis ZiriTadi mdgomareobis energia (1.33)fiqsirebul potencialur ormoSi gamoiTvleba (1.23), (1.30) <strong>da</strong> (1.32)formulebis <strong>da</strong>xmarebiT. gamoTvlebi iZleva eleqtronis energiis SemdegmniSvnelobas:4meΕ0=− 0,163 =−20,163⋅ hωα2 *20h ε2; Tu polarizaciuli potencialuriormo aris sakmaod Rrma, maSin masSi SesaZlebelia agreTve sxvadiskretuli energetikuli doneebis arseboba eleqtronisaTvis (ix. nax.1).nax.1. potencialuri ormo, energetikuli doneebi <strong>da</strong> eleqtronis Y -talRuri funqcia pekaris polaronis modelSiamrigad, pekaris polaronuli mdgomareobebi SesaZlebelia ganxiluliiqnes rogorc eleqtronisa <strong>da</strong> kristalis lokaluri polarizaciisbmuli (avtolokalizebuli) mdgomareobebi. es mdgomareobebi xasiaTdebianerTi an ramodenime diskretuli Sinagani energetikuli doneebis arsebobiTavtolokalizebuli eleqtronisTvis. gansxvavebiT polaronis frolixismodelisagan, romelic aRiwereba susti eleqtron-fononuriurTierTqmedebis α mudmivaTi ( α < 1), pekaris polaronuli mdgomareobebixorcieldeba mxolod α bmis mudmivas didi mniSvnelobebis dros ( α >> 1).aseTi avtolokalizebuli mdgomareobebi – polaronebi SesaZlebelia49


ga<strong>da</strong>adgildnen kristalSi, rogorc erTiani mTliani struqtura(kvazinawilaki), raRac efeqturi masiT – polaronis masiT.pekaris mier gamoTvlili iyo agreTve polaronis masa, rodesac polaroniasruleb<strong>da</strong> ga<strong>da</strong>taniT moZraobas kristalSi mcire siCqareebiT:V


Wrrkk , '=e2 0324πh 112Mω⎛1 Z⎞⎜ +7⎟⎝ ⎠N;( + Z )−1r r 2hω0⎡ ⎤ k'− kK BΤN = ⎢e − 1 ⎥ ; Z = ,2⎢⎣⎥⎦4 α '82(1.37)sa<strong>da</strong>c: α ' - sidide moicema (1.30) formuliT. mcire siCqareebiT moZravir2 2h kpolaronisTvis, rodesac


ganvixiloT axla dinamiuri modeli struqturulad Sedgenilikvazinawilakis–polaronis, romelic aRiwereba eleqtron-fononuri bmis α -mudmivas nebismieri mniSvnelobis dros, e.w. polaronis feinmanis modeli.1.3.2. polaronis feinmanis modelieleqtron-fononuri sistemisTvis <strong>da</strong> polaronis amocanaSi farTogamoyeneba hpova feinmanis kontinualuri integrebis meTodma (integralebitraeqtoriebis gaswvriv) [44-45]. am meTodis warmateba polaronis TermodinamikissakiTxebis ganxilvisas <strong>da</strong>kavSirebulia Semdeg mTavar teqnikurmomentebTan: 1) es meTodi SesaZlebels xdis, raTa moxdes zusti gamoricxvafononuri amplitudebisa polaronis amocani<strong>da</strong>n (problemi<strong>da</strong>n), ris Sedega<strong>da</strong>cmravalnawilakovani amocana <strong>da</strong>iyvaneba erTnawilakovani amocanisganxilvamde, romelic aRiwereba aralokaluri funqcionaliT <strong>da</strong> romelic<strong>da</strong>mokidebulia mxolod eleqtronis traeqtoriebze. polaronis feinmanismodelis formulirebisas fononuri operatorebi (amplitudebi)gamoiricxeba zustad eleqtron-fononuri sistemis qmedebi<strong>da</strong>n. amgvarad,miRebuli qmedeba, romelic ar aris lokaluri fononuri operatorebisgamoricxvis Semdeg eleqtron-fononuri sistemi<strong>da</strong>n, aRwers eleqtronisiseT moZraobas, rodesac amocana erTi nawilakis urTierTqmedebisa nawilakTausasrulo ricxvTan, <strong>da</strong>iyvaneba erTi nawilakis (eleqtronis) ur-TierTqmedebaze Tavis TavTan (TviTqmedebaze). 2) amocanis aseTi arsebiTigamartivebis Sedegad advili xdeba amoxsnebisTvis variaciuli meTodebisformulireba, <strong>da</strong>fuZnebuli iensenis utolobaze, romelic warmoadgensfunqcionalur analogs n.n. bogolubovis variaciuli principisa kvanturstatistikurisistemebis Tavisufali energiisTvis [25]. 3) miRebul funqcionalTa<strong>da</strong>xmarebiT, SesaZlebeli xdeba zustad amoxsnad modelTa klasisageba, romlebic Seesabamebian kvadratul funqcionalebs <strong>da</strong> romlebicgamoiyenebian rogorc miaxloebiTi modelebi variaciuli gamoTvlebisaTvis.feinmanis modelis (miaxloebis) arsi polaronis amocanisTvismdgomareobs imaSi, rom ganixileba zusti, aralokaluri qmedebis aprosimirebaaralokaluri kvadratuli qmedebiT. aralokalurobis gaTvaliswinebaanu “maxsovrobis” efeqtis CarTva qmedebaSi, aZlevs feinma-nismidgomas polaronis amocanisadmi unikalobis Tvisebas, polaronis sxva52


Teoriebisagan gansxvavebiT [46]. feinmanis sacdeli qmedeba aRwerseleqtrons, romelic urTierTqmedebs meore fiqtiur nawilakTan, romliskoordinatebis gamoricxva xdeba qmedebi<strong>da</strong>n–mas Semdeg, rac ganixilebaeleqtronis moZraoba ionur kristalSi <strong>da</strong> kristaluri me-sris rxevebis(fononebis) gavlena eleqtronze modelirdeba meore nawilakiT–romlismasaa MF <strong>da</strong> romelic urTierTqmedebs kvadratulad, k-urTierTqmedebismudmivaTi eleqtronTan. aseTi saxis sistemas, romelic aRwers eleqtronisurTierTqmedebas polarul optikur fononebTan, urTierTqmedebis (bmis) αmudmivas nebismieri mniSvnelobis dros, uwodeben polaronis feinmanis(erToscilatorian) models, romelic aris translaciurad invariantuli[44,46] (ix. nax. 2).nax.2. polaronis feinmanis modeli. eleqtroni, romelic <strong>da</strong>kavSirebulia“zambaris” meSveobiT meore nawilakTan masiT M Famrigad, polaronis feinmanis modelSi eleqtronisa <strong>da</strong> masTan<strong>da</strong>kavSirebuli virtualuri, korelirebuli fononebis “Rrublis” moZraobaaRiwereba eleqtronis urTierTqmedebiT fiqtiur nawilakTan. am modelishamiltonians aqvs Semdegi saxe [44,46]:r r2 2F Ρ ΡF1 r( ),2Hs= + + kr −rF(1.41)2m2MF2sa<strong>da</strong>c: Ρ r <strong>da</strong> Ρ rF- warmoadgenen eleqtronisa <strong>da</strong> fiqtiuri nawilakisimpulsis operatorebs, Sesabamisad; xolo r <strong>da</strong> r Farian eleqtronisa <strong>da</strong>fiqtiuri nawilakis radius-veqtorebi, m aris eleqtronis efeqturi masagamtarobis zoni<strong>da</strong>n, xolo M F – fiqtiuri nawilakis masa. (1.41) polaronisfeinmanis modeluri hamiltoniani aRwers nulovan miaxloebaSi polaronisaradisipaciur yofaqcevas eleqtron-fononuri urTierTqmedebis (bmis) αmudmivas nebismieri mniSvnelobis dros. Tu SemoviRebT axal kanonikurcvladebs, (1.41) hamiltoniani SesaZlebelia <strong>da</strong>viyvanoT diagonalur saxeze.marTlac gveqneba:53


aq:FHrPM + m r k r2FF 2 2s= + Ρos+ ros.2( m+MF) 2mMF2(1.42)r r rP =Ρ+Ρ - warmoadgens mTliani impulsis operators sistemisa, romelickanonikurad SeuRlebulia masaTa centris radius-veqtorTan:rrmr + MFrFR = ;m+MFxolo r os= r −rF- warmoadgens fardobiT koordinatas.r rr MFΡ−mΡFΡos=aris r oskoordinatis kanonikurad SeuRlebuli impulsi. (1.42)m+MFhamiltonianis energetikul speqtrs aqvs Semdegi saxe:r2PErr = + hν( h + h + h + 32);P, hx y z2( m+M )F( h , h , h = 0,1,2,...),x y z(1.43)xolo:M + mFν = k warmoadgens harmoniuli oscilatoris sixSires <strong>da</strong>mMFmMFM + mFaris sistemis <strong>da</strong>yvanili masa. MF+ m - sidide mocemul modelSi warmoadgenspolaronis efeqtur masas.Zlieri eleqtron-fononuri urTierTqmedebis SemTxvevaSi, rodesacα >>1, adgili aqvs utolobebs: M F>> m<strong>da</strong> ν >> ω0. feinmanis mier SemoRebuliiyo uganzomilebo parametrebi V <strong>da</strong> W, romlebic <strong>da</strong>kavSirebuliaM F <strong>da</strong> ν sidideebTan Semdegi tolobebiT:2⎡⎛V⎞ ⎤MF= m⎢⎜⎟ − 1; ⎥ ν = Vω 0;V <strong>da</strong> W⎢⎣⎝W⎠ ⎥⎦parametrebi ganisazRvrebodnen polaronis Tavisufali energiisminimizaciiT [44,46]. modelis yvela sxva <strong>da</strong>narCeni parametri, rogorebicarian: k, M F + m,mMFm+M <strong>da</strong> sxv. SesaZlebelia ganisazRvron ( m,ω0) <strong>da</strong> ( VW) ,Fparametrebis <strong>da</strong>xmarebiT. susti <strong>da</strong> saSualo siZlieris (intensivobis) eleqtron-fononuriurTierTqmedebis SemTxvevaSi ( α < 1): V >> W; MF→ 0; ν ≥ ω0;V ≥ 1; V≈ 1+α12[47]. (V <strong>da</strong> W variaciuli parametrebis yofaqcevis Sesaxebpolaronis feinmanis modelSi ix. nax. 3).polaronis problemisadmi variaciuli meTodis gamoyenebiT, feinmanismier napovni iyo polaronis ZiriTadi mdgomareobis energiis ze<strong>da</strong>54


sazRvari, kristaluri mesris (fononebis) nulovani temperaturis (T = 0)dros:32 αVE ≤ ( V −W)−4Vπ∞∫02{⎡2 2−UVWU + ⎡( V −W ) V⎤( 1−e) ⎤}⎣⎣( h = ω = m=1)0dUe−U⎦⎦12.(1.44)fononuri operatorebis (amplitudebis) gamoricxvis Sedegad miRebulzust qmedebas hqon<strong>da</strong> Semdegi saxe (gamoiyenebo<strong>da</strong> feinmanis meTodiintegralebi traeqtoriebis gaswvriv kristaluri mesris nulovanitemperaturis pirobebSi):1S =2∫r⎛ dr⎜⎝ dt2⎞⎟⎠dt −α8∞ ∞∫∫0 0− t−ser r dtdS.( t)−( s)(1.45)nax.3. V <strong>da</strong> W – variaciuli parametrebis yofaqceva,rogorc a-urTierTqmedebis(bmis) mudmivas funqciebi, polaronis feinmanis TeoriaSi(1.44) <strong>da</strong> (1.45) Tanafardobebis ganzogadoeba kristaluri mesrisnebismieri temperaturebis dros Sesrulebuli iyo [48] naSromSi. V <strong>da</strong> Wparametrebis varirebis Sedegad (1.44) formuli<strong>da</strong>n miiRebo<strong>da</strong> polaronisZiriTadi mdgomareobis energiis yvelaze saukeTeso umciresi ze<strong>da</strong>sazRvris Sefaseba α -bmis mudmivas sxva<strong>da</strong>sxva mniSvnelobebis dros:55


1) α -s mcire mniSvnelobebis dros ( α < 1), V <strong>da</strong> W-s saukeTesomniSvnelobebia: V = 31 [ + 2 α (1 −Ρ)3W], sa<strong>da</strong>cW-s am mniSvnelobebisaTvis polaronisSefaseba:12 ⎡(1)12W 1Ρ= ⎣ − −W⎤⎦<strong>da</strong> W = 3. V <strong>da</strong>E-energiisaTvis gveqneba Semdegi2 3 2 3E ≤−α − α +Ο ( α ) =−α − 0.0123 α +Ο( α ).(1.46)81xolo SeSfoTebis Teoriis Sedegad miRebuli rezultati tolia sididis2E =−α − 0.0126 α + ...(1.47)2) α -s didi mniSvnelobebis SemTxvevaSi, rodesac ( α >> 1), V <strong>da</strong> W-ssaukeTeso mniSvnelobebisTvis gvaqvs:V2= α + +4 ⎛ C ⎞4⎜ln2 ⎟ 1, sa<strong>da</strong>c C - eiler-9π⎝ 2 ⎠maskeronis mudmivaa: C = 0,5772... <strong>da</strong> W = 1. am SemTxvevaSi polaronisenergiisTvis gveqneba Sefaseba:2α 3 3 ⎛ 1 ⎞E ≤− − ( 2ln2 + C)− +Ο + ...23π2 4⎜ ⎟⎝α⎠(1.48)rogorc me-3 nax. naTlad Cans, V <strong>da</strong> W variaciuli parametrebi,polaronis feinmanis modelSi, warmoadgenen bmis α -mudmivas uwyvetfunqciebs. ricxviTi gamoTvlebis Sedegad miRebuli iyo polaronisZiriTadi mdgomareobis energiis <strong>da</strong>mokidebuleba bmis mudmivaze. GgamoTvlebmaaCvena, rom polaronis ZiriTadi mdgomareobis energiismniSvneloba pekaris TeoriaSi:2E0 =−0.326α (0hω -erTeulebSi) – ufro mciresididisaa, vidre polaronis feinmanis TeoriaSi, rodesac α > 34.29.saerTod ki un<strong>da</strong> aRiniSnos, rom polaronis ZiriTadi mdgomareobisenergiis Sefaseba feinmanis TeoriaSi bevrad ufro mcirea yvela sxvaSefasebebTan Se<strong>da</strong>rebiT, romlebic miiReba polaronis sxva Teoriebis saSualebiT;gar<strong>da</strong> amisa, un<strong>da</strong> aRiniSnos agreTve is garemoebac, rom feinmanismeTods gaaCnia didi upiratesoba sxva meTodebTan Se<strong>da</strong>rebiT polaronisTeoriebSi, vinai<strong>da</strong>n es meTodi (integralebi traeqtoriebis gaswvriv)iZleva saSualebas rom vipovoT polaronis energiis Sefasebebi bmis α -mudmivas rogorc mcire, aseve saSualedo <strong>da</strong> didi mniSvnelobebis dros;Tanac es meTodi iZleva erTaderT saimedo Sedegebs α -bmis mudmivas saSualedo(5< α < 10 ) mniSvnelobebisaTvis [46,49].56


funqcionalur-variaciuli meTodis <strong>da</strong>xmarebiT feinmanis mier gamoTvliliiyo agreTve polaronis efeqturi masis sidide [44,46]. integralebiTtraeqtoriebis gaswvriv miaxloebiT gamoTvlas – polaronis feinmanismodelis qmedebisTvis _ mivyavarT polaronis efeqturi masis Semdeggamosaxulebamde:−323 ∞2* αV−τ2⎡V −1−VWτ⎤mF= 1+ ⎢ + ( 1 − ) ⎥ ( = 1).3∫ dτe τ τe mπ0 ⎣ VW ⎦(1.49)(1.49) formulaSi V <strong>da</strong> W variaciuli parametrebis optimaluri mni-Svnelobebis CasmiT SesaZlebelia Sefasebuli iqnasm * Fefeqturi masa α -bmis parametris mniSvnelobaTa mTel intervalSi. mcire siCqareebiT moZravifeinmanis polaronis efeqturi masis (1.49) mniSvneloba susti <strong>da</strong> Zlierieleqtron-fononuri urTierTqmedebis zRvrul SemTxvevebSi warmoidginebaSemdegi saxiT:2* α 2αmF = 1 + + ; α >1.rasakvirvelia, (1.49-1.50) gamosaxulebebi samarTliania kristalisnulovani temperaturis (T=0) SemTxvevaSi. (1.50) gamosaxulebebi efeqturimasisaTvis ZiriTadi rigiT α -parametris mixedviT emTxveva, Sedegebsgamomdinare rogorc SeSfoTebis Teorii<strong>da</strong>n ( α > 1).sainteresoa aRiniSnos is garemoeba, romm * Fefeqturi masis mniSvnelobebi,romlebic napovnia (1.49) gamosaxulebi<strong>da</strong>n mxolod umniSvnelod(ramodenime procentiT) gansxvavdeba sacdeli modelis sruli masismniSvnelobisagan:MF1 ⎛ V+ = ⎞⎜ ⎟⎝W⎠2(m – eleqtronis efeqturi masiserTeulebSi). sasruli temperaturebis dros, polaronis feinmanis Teoriisformulirebisas gamoiTvlebo<strong>da</strong> gibsis operatoris kvali, traeqtoriebisgaswvriv integralebis meTodis gamoyenebiT, Zlieri eleqtron-fononuriurTierTqmedebis SemTxvevaSi [48]. eleqtron-fononuri sistemis mdgomareobaTaerToblioba <strong>da</strong>kavSirebulia helmholcis Tavisufali energiis57


mniSvnelobebTan, romlis minimizacia xdebo<strong>da</strong> V <strong>da</strong> W parametrebismixedviT mocemuli, fiqsirebuli temperaturis pirobebSi; amgvaradganisazRvrebo<strong>da</strong> polaronis saSualo energia, rogorc temperaturisfunqcia. temperaturis zr<strong>da</strong>sTan erTad (α -parametris fiqsirebulimniSvnelobis dros), polaronis saSualo energiisa <strong>da</strong> misi efeqtur masismniSvnelobebi mcirdeba. polaronis saSualo energiisa <strong>da</strong> efeqturi masisaseTi yofaqceva, rodesac Τ→∞ , E → 0 <strong>da</strong> m → 0 [48] naSromSi aixsnebaimiT, rom vinai<strong>da</strong>n Zalian <strong>da</strong>bali temperaturebis dros fononebi arian“Tavisufali”, maTi entropia izrdeba im fononebis entropiasTanSe<strong>da</strong>rebiT, romlebic <strong>da</strong>kavSirebuli arian eleqtronTan.eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis TeoriaSiarsebul im mravalricxovan gamokvlevaTa Soris, romelic miZRvniliapolaronis feinmanis modelis kinetikis sakiTxebisadmi, gansakuTrebulimniSvneloba eniWeba naSromebs, romlebSiac gamokvleulia polaronisZvradoba <strong>da</strong> eleqtrogamtaroba. es gamokvlevebi <strong>da</strong>myarebulia grinisfunqciaTa meTodze [50] bolcmanis kinetikuri gantolebis Seswavlaze [51-52], TviTSeTanxmebuli <strong>da</strong> feinmanis kontinualuri integrebis meTodebisgamoyenebaze [53-54], kubos wrfivi gamoZaxilis Teoriaze [55-56] <strong>da</strong> sxv.rogorc wesi, rezultatebi miRebuli am sxva<strong>da</strong>sxva meTodebis <strong>da</strong>xmarebiT,romlebSiac gamoiyeneba sxva<strong>da</strong>sxva miaxloebebi, aris sxva<strong>da</strong>sxva (zogjerarsebiTa<strong>da</strong>c gansxvavdeba erTmaneTisagan). un<strong>da</strong> aRiniSnos, rom zoga<strong>da</strong>dpolaronis kinetikis ganxilvisas yvela zemoT CamoTvlili meTodiiTvaliswinebs ZiriTadi mdgomareobis energiis Semcirebas <strong>da</strong>kvazinawilakis maxis gazr<strong>da</strong>s fononebTan urTierTqmedebis Sedegad,romelic gamowveulia eleqtron-fononuri urTierTqmedebis didi nawilisgaTvaliswinebiT. <strong>da</strong>rCenili eleqtron-fononuri urTierTqmedeba (e.w. “nar-Ceni” urTierTqmedeba) aRwers polaronis gabnevas realur (siTbur)fononebze <strong>da</strong> iZleva Sesworebebs polaronis ZiriTadi mdgomareobisenergiisaTvis <strong>da</strong> efeqturi masisTvis.amgvarad, TviT sakuTriv polaronis feinmanis modelSi, eleqtronisurTierTqmedebas polarizaciul velTan mivyavarT arsebiTad or,erTmaneTisagan gansxvavebul movlenasTan (efeqtTan):1) eleqtroni garSemortymulia virtualuri fononebis “RrubliT”.sakmarisad Zlieri eleqtron-fononuri urTierTqmedebis SemTxvevaSi,58F


struqturulad Sedgenil kvazinawilaks – polarons gaaCnia Sinaganimdgomareoba. es “Cacmis” efeqti, romelic aris Sedegi virtualurifononebis gamosxivebisa <strong>da</strong> STanTqmisa, nulovan miaxloebaSi aRiwerebafeinmanis modeluri hamiltonianiT (1.41).2) disipaciis efeqti. es efeqti, romelic arsebiTad gansxvavdeba pirvelisagan,aRwers polaronis disipaciis movlenas; eleqtroni, fononurvelTan urTierTqmedebis Sedegad - asxivebs <strong>da</strong> STanTqavs realur (siTbur)fononebs, ris gamoc ga<strong>da</strong>dis erTi stacionaruli mdgomareobi<strong>da</strong>n meoreSi,magaliTad gareSe velis zemoqmedebis Sedegad. TviT polaronisurTierTqmedeba realur fononebTan am modelSi moicema frolix-pekaris(1.13) urTierTqmedebis hamiltonianiT, sa<strong>da</strong>c V rksidideebi ganisazRvreba(1.18) TanafardobebiT.amgvarad, feinmanis kontinualuri integrebis formalizmisa <strong>da</strong>funqcionaluri-variaciuli meTodis gamoyenebiT SesaZlebeli xdeba er-Tiani midgomis farglebSi aRweril iqnas polaronis amocana α -bmismudmivas nebismieri mniSvnelobis dros, Tanac α -mudmivas mniSvnelobaTafarTo intervalSi vRebulobT polaronis ZiriTadi mdgomareobis energiisSefasebas bevrad ufro zusts, vidre sxva cnobili meTodebis <strong>da</strong>miaxloebebis gamoyenebisas; am formalizmis <strong>da</strong>xmarebiT SesaZlebeliagamoTvlil iqnas TiTqmis yvela statikuri (Termodinamikuri) <strong>da</strong> dinamiurisidide, romelic ki warmoadgens interess polaronis amocanisTvis didiradiusis mqone polaronis TeoriaSi. rasakvirvelia, ar arsebobs winaswargarantia imisa, rom kargi miaxloeba polaronis Tavisufali energiisTvisaseve kargad aRwers polaronis sxva fizikur maxasiaTeblebs (zogierTSemTxvevaSi, marTlac es ase ar aris), magram zoga<strong>da</strong>d un<strong>da</strong> iTqvas, romfunqcionalur-variaciuli midgoma SesaZlebels xdis polaronulisistemis yofaqcevis erTiani suraTis Camoyalibebas α -bmis parametris mniSvnelobaTafarTo intervalSi, kristalis sxva<strong>da</strong>sxva temperaturis dros,gareSe velebis sxva<strong>da</strong>sxva <strong>da</strong>Zabulobebisa <strong>da</strong> sixSireebis SemTxvevaSi <strong>da</strong>sxv.magram miuxe<strong>da</strong>vad polaronis feinmanis modelis unikalobisa, am modelsacgaaCnia erTgvari SemosazRvruloba. rogorc ukve iyo aRniSnuli,feinmanis polaronis TeoriaSi xdeba zusti, aralokaluri qmedebismiaxloeba aralokaluri kvadratuli qmedebiT, rac adebs erTgvarad Sez-59


Rudvas urTierTqmedebis potencialis formas, romelic Semoifarglebamxolod harmoniuli urTierTqmedebiT. Ggar<strong>da</strong> amisa, Zlieri eleqtronfononuriurTierTqmedebis SemTxvevaSi naTlad ar Cans kavSiri polaronisfeinmanis Teoriasa <strong>da</strong> polaronis pekaris models Soris.polaronis feinmanis modelis ganzogadoeba Sesrulebuli iyo [57-58]naSromebSi. gansxvavebiT polaronis feinmanis modelisagan, ganzogadoebulmodelSi ar xdebo<strong>da</strong> qmedebis aproqsimireba aralokaluri kvadratuliqmedebiT, anu urTierTqmedebis potenciali fiqtiur nawilakTan ar iyoharmoniuli tipis; ufro metic, eleqtronis urTierTqmedebis potencialifiqtiur nawilakTan ar iyo fiqsi-rebuli saxis - am potencialis povnaxdebo<strong>da</strong> variaciuli meTodis gamoyenebiT [57-58]. mimovixiloT axlaSe<strong>da</strong>rebiT ufro <strong>da</strong>wvrilebiT polaronis feinmanis ganzogadoebulimodeli (fgm).1.3.3. polaronis feinmanis ganzogadoebuli modeli(latinjer-lus modeli)polaronis feinmanis modelisagan gansxvavebiT fgm-Si, eleqtronisa<strong>da</strong> masTan <strong>da</strong>kavSirebuli virtualuri, korelirebuli, optikuri fononebis“Rrublis” moZraobis aproqsimireba xdeba eleqtronis traeqtoriiT,romlis drosac eleqtroni urTierTqmedebsMGFmasis mqone fiqtiur nawilakTanVGFpotencialis meSveobiT. Se<strong>da</strong>rebiT yvelaze ufro martivSemTxvevaSi aseTi sistemis (eleqtroni+fiqtiuri nawilaki) hamiltonianiaiReba Semdegi saxiT [57]:r r2 2s Ρ ΡGFr rHGF = + + VGF ( − RGF),(1.51)2 2MGFr rsa<strong>da</strong>c: Ρ , R <strong>da</strong> MGFwarmoadgenen impulsis operators, radius-veqtorsGFGF<strong>da</strong> masas fiqtiuri nawilakisa, Sesabamisad. gamoTvlebis gamartivebismizniT, Cven SemovisazRvrebiT erTeulTa sistemiT, romelSiac: h = m = ω0 = 1. .(1.51) formulaSi, <strong>da</strong>Svebulia, rom eleqtroni urTierTqmedebs fiqtiurrV − Rr- centraluri, Zaluri potencialiT. Tu SemoviRebTnawilakTanGF( GF )axal kanonikur cvladebs, SesaZlebelia (1.51) hamiltonianis <strong>da</strong>yvanadiagonalur saxeze <strong>da</strong> misi warmodgena Semdegi formiT:60


HrPM+ 1 r2sGF 2GF= + Ρ1GF + VGF2( MGF+ 1)2MGFr( ξ ).(1.52)r r raq: P= Ρ+ΡGFaris sistemis sruli impulsis operatori, romelic kanonikuradSeuRlebulia masaTa centris radius-veqtorTan: R =;rrr−RGFMGFMGF+ 1r rr r rr MGFΡ−ΡGFξ =−R GFwarmoadgens fardobiT koordinatas, xolo Ρ 1 GF=arisM + 1Sesabamisi impulsi. un<strong>da</strong> aRiniSnos, rom sidide MGF+ 1 mocemulmiaxloebaSi warmoadgens polaronis efeqtur masas fgm-Si; TviT V GFpotencializoga<strong>da</strong>d ar aris fiqsirebuli, misi forma (saxe) moiZebnebavariaciuli principi<strong>da</strong>n mocemul modelSi (SevniSnavT, rom polaronisfeinmanis modelSi Teoriis variaciul parametrebs warmoadgenen k <strong>da</strong>sidideebi).[57-58] naSromebSi ganzogadoebuli iqna feinmanis kontinualuri integrebismeTodi (feinmanis formalizmi – integralebi traeqtoriebisgaswvriv), romlis <strong>da</strong>xmarebiTac <strong>da</strong> iensenis utolobis gaTvaliswinebiT,GFMFmiRebuli iyo optikuri polaronisTvis energiis mniSvnelobaGFΕ 0, rogorcqve<strong>da</strong> sazRvari variaciuli energiisaGFΕV, ise rom ar iyo fiqsirebuliforma (saxe) V GFvariaciuli potencialisTvis.MGFsa<strong>da</strong>c: µ = ;M + 1r2∞Ρr rGF GF 1GFαΕ0 ≤ΕV= u0 u0− ∑ ' ×2∫∫dξdξµ 2µn=0r r r rr r12* * ⎧1 exp 2 (1 ) ' ⎫u0( ξ ') u0( ξ ) u ( ) ( ') − ⎡− +∆ − ⎤⎪ ⎣nnξ unξC ε ξ ξ⎦⎪× r r ⎨ ⎬,ξ −ξ' ⎪ 1+∆εn⎩⎪⎭GF∆ ε = ε − εnn0 ;C =MGF2( M + 1)GFr<strong>da</strong>: u ( ξ ) <strong>da</strong>n(1.53)εnwarmoadgenensakuTar funqciebs <strong>da</strong> sakuTar mniSvnelobebs Sredingeris gantolebisa,arafiqsirebuli (ganusazRvreli) variaciuli potencialiT V GF:⎡ 1⎤− ∆ r⎢ + ( ) ( ) = ( );2⎥⎣V r r rGFξ⎦u nξ ε u n nξξµ (1.54)( n = 0,1,2,...).(1.52) hamiltonianis cxadi saxe gviCvenebs, rom Sredingeris gantolebasistemisaTvis (eleqtroni+fiqtiuri nawilaki) SesaZlebelia ganvacalkevoT61


<strong>da</strong> CavweroT rogorc (1.54) Sredingeris gantoleba VGF( ξ r ) potencialiT, <strong>da</strong>ragreTve Semdegi saxis Sredingeris gantoleba Ψ r ( R)talRuriPfunqciisTvis:⎡ 1 1 ⎤ r r⎢− ∆ Ψ ( R) =ΕΨ( R),2M1 Rr r r r⎥(1.55)P P P⎣ GF+ ⎦sa<strong>da</strong>c: sistemis sruli energia Ε GF r moicema TanafardobiTP , nr2GFPrrr1 iPRΕ r =Ε r + ε,, nn≡ + εPPnxolo Ψ r ( R)= e warmoadgens brtyel talRas,P2( + 1)VM GFromelic normirebulia sistemis V moculobaze.vinai<strong>da</strong>n (1.53) gantolebis yvela wevri, romelic figurirebs ajamvissimbolos qveS, warmoadgens <strong>da</strong>debiT sidides, amitom cxadia, rom Tu CvenSemovisazRvrebiT mxolod ZiriTadi wevriT (h=0) (1.53) gantolebis marjvenanawilSi, maSin am gantolebis marjvena mxare gaxdeba ze<strong>da</strong> sazRvaripolaronis energiisTvis. ZiriTadi mdgomareobis miaxloebaSi Cven gveqneba:rr r2* Ρ r r rGF GF 1GFαΕ0 ≤ΕV= ∫dξu0( ξ) u0( ξ) − ' ⋅2 2∫∫dξdξµ µGF 0GFr r 2Eu0( ξ ) u0( ξ ')v= Ev(1.56)r r⋅ r r { 1−exp⎡−2 C ξ −ξ' ⎤}.ξ − ξ ' ⎣ ⎦rvinai<strong>da</strong>n (1.56) funqcionali Seicavs µ <strong>da</strong> u0( ξ ) sidideebs, SesaZlebeliaam sidideebis varireba, imisaTvis, rom vipovoT Ε 0GF V( µ , u0)energiisminimaluri mniSvneloba. Tu gamoviyenebT ritcis variaciul princips(meTods) pekaris tipis sacdeli talRuri funqciebiT, romelsac aqvsSemdegi saxe:r3 32 2 2 −bµξ 2 2bµu0( ξ ) = N( 1 + bµξ + ab µξ ) e ; N =,2π(14+ 42a+45 a )(1.57)sa<strong>da</strong>c a <strong>da</strong> b warmoadgenen variaciul parametrebs, maSin SesaZlebelia gamoTvliliqnasE0GFV( µ , ab , ) - polaronis ZiriTadi mdgomareobis energiisminimaluri mniSvneloba. SesaZlebelia agreTve gamoyenebuli iqnasvariaciuli meTodi pir<strong>da</strong>piri integrirebisa. vinai<strong>da</strong>n E 0GFVwarmoadgens µr(<strong>da</strong>yvanili masis) parametris funqcias <strong>da</strong> u 0( ξ ) funqciis funqcionals, <strong>da</strong>rSeicavs <strong>da</strong>matebiTi pirobis saxiT mxolod u0( ξ ) funqciis normirebas:62


∫r r 2dξ u0( ξ ) = 1, amitom moTxovna saukeTeso (optimaluri) urTierTqmedebispotencialis SerCevisa (romelic ganapirobebs polaronis ZiriTadi mdgomareobis-E0GFV( µ , ab , ) energiis minimaluri mniSvnelobis miRebas)ekvivalenturia Semdeg gantolebaTa sistemisa:δrδu( ξ)0δEδµ0GFVr r0GF{ E ∫ }2Vλ dξ u0ξ= 0.− ' ( ') = 0;(1.58)amrigad, amocana faqtiurad <strong>da</strong>iyvaneba µ sididis TiToeulimniSvnelobisaTvis, hartris saxis TviTSeTanxmebuli Sredingerisgantolebis amoxsnamde:rr 22Ρ r12 r 0( ')r rGFα u ξu ( ξ ) − ' ⎡1−exp( −2 − ') ⎤×02∫dξ r rC ξ ξµ µ ξ −ξ' ⎣⎦r r× u ( ξ) = ε u ( ξ).0 0 0amitom, aseTi miaxloebis drospotencialisTvis gveqneba Semdegi saxis gamosaxuleba:r 2r0 α 2 r u0( ξ ')r rV ( ) =− ∫ ' ⎡1−exp( −2 − ') ⎤GFξ dξ r r.− ' ⎣C ξ ξµ ξ ξ⎦(1.59)V GFTviTSeTanxmebuli variaciuli(1.60)(1.56-1.57) <strong>da</strong> (1.59) gantolebebis <strong>da</strong>xmarebiT SesaZlebelia aRdgenili(miRebuli) iqnas pekaris naxevradklasikuri Teoria [30,58]. Zlierieleqtron-fononuri urTierTqmedebis SemTxvevaSi ( α >> 1), rodesacrM >> 1, ( ε0 >> hω0) <strong>da</strong> C →∞. (1.60) gantolebis Tanaxmad V0 ( ξ )GFpotencialisTvis gveqneba gamosaxuleba:r 2r0 α 2 r u0( ξ ')VGF( ξ) =− ∫dξ' r r .µ ξ −ξ'(1.61)susti eleqtron-fononuri urTierTqmedebis SemTxvevaSi ( α < 1), rodesacM → 0 , µ → 0, C → 0 , Tu (1.56), (1.60) formulebis, integralqveSaGFgamosaxulebebSi gavSliT eqsponentas mwkrivad, maSin martivad <strong>da</strong>vrwmundebiT,rom am zRvrul SemTxvevaSi polaronis energia fgm-Si Semosaz-Rvrulia mniSvnelobiT: −α , anu E ≤− 0α . zogad SemTxvevaSi, polaronisGF63


E0GFV( µ , ab , ) energiis mniSvneloba SesaZlebelia gamoTvlil iqnasanalizurad Tu gamoviyenebT Semdeg cnobil formulebs:r rexp ( ik ξ −ξ') ∞ + e(1) *r r = ik∑Ie( kξ < ) hl ( kξ > ) ∑Ylm( θϕ , ) Ylm( θϕ , );4 πξ −ξ'l= 1m=−ln! n!ZZnkn −bt −bZ∫te dt = −en+ 1 ∑ n− k+1b0k=0 k!b∞∫Zte dt = en −bt −bZ∞∑k = 0n!Zk!bkn− k+1.;(1.62)polaronis energiisE0GFV( µ , ab , ) mniSvneloba gamoTvlili iyo [58]naSromSi. Zlieri eleqtron-fononuri urTierTqmedebis SemTxvevaSi ( α >> 1)polaronis energiis ze<strong>da</strong> sazRvris mniSvneloba tolia sididis:−0,108504α2[57-58].ricxviTi meTodebis gamoyenebiT, TviTSeTanxmebuli (1.60) potencialirrogorc sawyisi potenciali, saSualebas iZleva rom gamovTvaloT u ( ξ )aRgznebuli talRuri funqciebi, Sredingeris (1.59) gantolebis <strong>da</strong>xmarebiT.polaronis fgm-Si, TviTSeTanxmebul potencialis yofaqceva did manZilzearis kulonuri tipis, xolo mcire manZilze (areSi, sa<strong>da</strong>c eleqtronistalRuri funqcia aris didi) potenciali aris paraboluri saxis(harmoniuli oscilatoris potencialis tipis) [30,57-58]. gansxvavebiT polaronisfeinmanis modelisagan, am modelSi martivad xerxdeba miRebuliSedegebis (magaliTad: polaronis ZiriTadi mdgomareobis energiis)<strong>da</strong>kavSireba SedegebTan, romlebic gamomdinareoben polaronis pekarisTeorii<strong>da</strong>n, Zlieri eleqtron-fononuri urTierTqmedebis SemTxvevaSi. [58]naSromSi naCvenebia, rom midgoma, romelic eyrdnoba variaciuli meTodisgamoyenebas optimaluri, TviTSeTanxmebuli potencialis sapovnelad, uke-Tes Sedegs iZleva polaronis ZiriTadi mdgomareobis energiis gamoTvlisas,vidre harmoniuli aproqsimacia urTierTqmedebis potencialisTvis.iseve rogorc polaronis feinmanis modelSi, polaronis fgm-Si (1.51)modeluri hamiltoniani aRwers nulovan miaxloebaSi polaronisaradisipaciur yofaqcevas, α-parametris nebismieri mniSvnelobis dros.amrigad, polaronis fgm-Sic, eleqtronis urTierTqmedebas polaruloptikur fononebTan mivyavarT or gansxvavebul efeqtTan. erTi efeqtiganapirobebs polaronis - rogorc kvazinawilakis struqturis Camoya-n64


libebas, romelic aris Sedegi virtualuri fononebis gamosxivebisa <strong>da</strong>STanTqmisa <strong>da</strong> romelsac adgili aqvs Zlieri eleqtron-fononuri urTierTqmedebisdros <strong>da</strong> meore efeqti, romelic gansxvavdeba pirvelisagan <strong>da</strong>romelic aRwers polaronis disipaciis movlenas, ganpirobebuls eleqtronisurTierTqmedebiT siTbur polarul optikur fononebTan. esukanaskneli efeqti, iseve rogorc polaronis feinmanis modelSi, aRiwerebafrolix-pekaris tipis - (1.13) urTierTqmedebis hamiltonianiT.miuxe<strong>da</strong>vad kontinualuri integrirebis (integralebi traeqtoriebisgaswvriv) meTodis upiratesobisa sxva meTodebTan Se<strong>da</strong>rebiT <strong>da</strong> funqcionalur-variaciulimidgomis <strong>da</strong>debiTi mxareebisa, romlebsac CvenSevexeT polaronis feinmanis modelisa <strong>da</strong> fgm-is ganxilvis dros,wonasworul <strong>da</strong> arawonasworul statistikur meqanikaSi <strong>da</strong>, kerZodpolaronuli sistemebis Termodinamikisa <strong>da</strong> kinetikis sakiTxebis SeswavlisasfarTo gamoyeneba hpova mowesrigebul operatorTa formalizmma<strong>da</strong> T-namravlTa meTodma, romelic agreTve emyareba fononuri amplitudebisgamoricxvis teqnikas [59-62]. ufro metic, SeiZleba iTqvas, rom zogierTiSedegi polaronis TeoriaSi pirvelad miRebul iqna swored am midgomisgamoyenebiT. gar<strong>da</strong> amisa, mowesrigebul operatorTa formalizmsa <strong>da</strong> T-namravlTa meTods eniWeba upiratesoba zogierTi sakiTxis ganxilvisas,gansakuTrebiT maSin, rodesac saWiroa rezultatebis marTebulobissafuZvlianobisa <strong>da</strong> zogierTi Teoremebis <strong>da</strong>mtkiceba statistikur meqanikaSi,<strong>da</strong> kerZod, polaronis TeoriaSi [60-62].gasuli saukunis 80-ian wlebSi n.n. bogolubovisa <strong>da</strong> n.n. bogolubov(umc.) mier ganviTarebul iqna axali midgoma eleqtron-fononurisistemisaTvis <strong>da</strong> polaronis wonasworul TeoriaSi (ganixilebo<strong>da</strong>eleqtronis urTierTqmedeba polarul optikur fononebTan), romelicsamarTliania nebismieri temperaturebisa <strong>da</strong> eleqtron-fononuriurTierTqmedebis α-parametris nebismieri mniSvnelobis dros. am midgomassafuZvlad edo T-namravlTa teqnikis gamoyeneba fononebis Tavisuflebisxarisxis gamosaricxad eleqtron-fononuri sistemi<strong>da</strong>n, <strong>da</strong> Sesabamisadeleqtron-fononuri sistemis maxasiaTebeli fizikuri sidideebis wonasworulisaSualo mniSvnelobebis gamoTvla [62]. T-namravlTa teqnikasaSualebas iZleva mkacri maTematikuri sizustiT <strong>da</strong> Se<strong>da</strong>rebiT martivdoneze <strong>da</strong>asabuTos kontinualuri integrebis meTodis safuZvlianobis idea65


[14-15]. zustad amoxsnadi hamiltonianisa <strong>da</strong> agreTve variaciuli principisgamoyenebam polaronis TeoriaSi, SesaZlebeli gaxa<strong>da</strong> polaronis Tavisufalienergiis ze<strong>da</strong> sazRvris Sefaseba sasruli temperaturebisa <strong>da</strong> α-bmismudmivas nebismieri mniSvnelobis dros [40,62]. un<strong>da</strong> aRiniSnos, rommowesrigebul operatorTa formalizmi <strong>da</strong> T-namravlTa teqnika gansakuTrebiTefeqturi aRmoCn<strong>da</strong> polaronis Tavisufali energiisgamosaTvlelad SeSfoTebis Teoriis meTodebis gamoyenebisas sasrulitemperaturebis SemTxvevaSi <strong>da</strong> agreTve eleqtron-fononuri sistemis(polaronis) kinetikis sakiTxebis ganxilvisas [5,14-16,62].axla ga<strong>da</strong>videT fizikuri kinetikis zogierTi principuli sakiTxismimoxilvaze dinamiuri sistemebisa, romlebic urTierTqmedeben bozonur(fononur) TermostatTan.1.4. fizikuri kinetikis zogierTi sakiTxi dinamiuri sistemebisa, romlebicurTierTqmedeben fononur(bozonur) velTanrogorc cnobilia, kinetikuri gantolebebis miRebis Cveulebriviprocedura <strong>da</strong>kavSirebulia korelaciebis Sesustebis hipoTezasTan anekvivalentur <strong>da</strong>SvebebTan, magaliTad Sfm-Tan. es hipoTeza an miaxloebasaSualebas iZleva rom moxdes sistemis Semoklebuli aRwera kinetikurigantolebis saxiT. magram, rogorc cnobilia, dinamiur sistemebSi mimdinarestohastikuri procesebis Teorii<strong>da</strong>n, Tu dinamiuri sistema warmoadgens Ktipis sistemas (a.n. kolmogorovis saxis sistemebi) [20,63], maSin araviTarihipoTeza ar aris saWiro kinetikuri gantolebis misaRebad, SemoklebuliaRwera warmoiqmneba avtomaturad dinamiuri sistemis evoluciis procesSifazur sivrceSi Serevis procesebis arsebobis gamo erT-erTi an ramdenimedinamiuri cvladis mixedviT. swored am cvladis an cvladebis mixedviTxdeba korelaciebis swrafi Sesusteba. analogiuri debuleba samarTlianiaagreTve kvanturi - K sistemebisaTvis. tradiciulad, rogorc wesi,kinetikuri gantolebis gamoyvanas Tan axlavs specifiuri tipis apriorulihipoTeza. kargad aris cnobili, rom kinetikuri gantolebis forma <strong>da</strong>struqtura ganisazRvreba im procesebis albaTuri bunebiT <strong>da</strong> TvisebebiT,romlebsac aRwers TviT es gantoleba. Tu gamovalT liuvilisgantolebi<strong>da</strong>n ganawilebis funqciisTvis (kvantur-meqanikuri midgomisas66


fon-neimanis gantolebi<strong>da</strong>n statistikuri operatorisTvis), Cven SegviZliavipovoT kinetikuri gantolebis saxe, Tu ugulvebelvyofT wevrebs romel-Ta gamo moZraobis dinamiuri xasiaTi arsebiTad gansxvavdeba SemTxveviTiprocesebisagan. amis gamo kinetikuri gantolebis miRebas ama Tu im formiTTan axlavs raime principis an aprioruli hipoTezis formulireba, <strong>da</strong>amitom aseTi hipoTezis arsi (<strong>da</strong>tvirTva) mdgomareobs imaSi, rom mocemulidinamiuri sistemisTvis SemoaqvT SemTxveviTobis (qaosis) esa Tu is elementi[3,20].im meTodebs Soris, romlebsac mivyavarT kinetikuri gantolebismiRebamde, yvelaze ufro srulyofili ganviTareba <strong>da</strong> gamoyeneba hpova n.n.bogolubovis meTodma, romelic ga<strong>da</strong>bmuli gantolebebis ierarqiulijaWvis <strong>da</strong>xmarebiT saSualebas iZleva ganawilebis funqciis agebisa, <strong>da</strong>romelic gamomdinareobs liuvilis gantolebi<strong>da</strong>n. es meTodi cnobilia,rogorc – bbgki-is (bogolubovi-borni-grini-kirkvudi-ivoni) saxelwodebiT.bbgki-is jaWvi sabolood mTavrdeba bolcmanis tipis gantolebis miRebiT.am meTodSi gamoiyeneba sivrculi korelaciebis Sesustebis principi,romelic mdgomareobs imaSi, rom nawilakebi romlebic sakmao manZiliTarian <strong>da</strong>cilebuli erTmaneTisagan sivrceSi, asruleben arakorelirebadmoZraobas [4,34,64-65].un<strong>da</strong> aRiniSnos, rom fun<strong>da</strong>menturi miRwevebi bolcmanis tipiskinetikuri gantolebis (rogorc klasikuris, aseve kvanturis) <strong>da</strong> ZiriTadikinetikuri gantolebis gamoyvanaSi, miuZRvis n.n. bogolubovs. bolcmanissaxis kvantur-kinetikuri gantoleba mkacri saxiT miRebuli iqna n.n.bogolubovis mier, romelic eyrdnobo<strong>da</strong> korelaciebis SesustebishipoTezas [36,66]. mis mier <strong>da</strong>muSavebuli iyo formaluri sqemebi zoga<strong>da</strong>dkinetikuri gantolebebis miRebisa <strong>da</strong> formulirebuli iyo mkacrimaTematikuri formiT is <strong>da</strong>Svebebi, romlebic avseben <strong>da</strong>matebiT amgamoyvanebis meTodebs. kvanturi kinetikuri gantolebis sxva formac –ZiriTadi kinetikuri gantoleba (master equation), romelic pirvelad SemoTavazebuliiyo paulis mier – gamoyvanili iyo n.n. bogolubovis mier Sfm-Si,romlis miRebis drosac gamoyenebuli iyo SeSfoTebis operatorisspeqtraluri Tvisebebi [36,66].K-tipis dinamiuri sistemebisaTvis (rogorc klasikuris, asevekvanturisTvis), SesaZlebelia paulis saxis kvanturi kinetikuri gantole-67


is miReba Sfm-is gamoyenebis gareSe. aseTi saxis gantolebis miReba demonstrirebuliiyo [20] naSromSi, kvanturi arawrfivi oscilatorismagaliTze, romelze<strong>da</strong>c moqmedeb<strong>da</strong> gareSe perioduli Zala. meTodisZiriTadi idea, romelic gamoyenebuli iyo [20] naSromSi mdgomareob<strong>da</strong>imaSi, rom kvanturi K sistemebis ergodiul Tvisebebs klasikur zRvrulSemTxvevaSi mivyavarT statistikuri operatoris aradiagonalurimatriculi elementebis swraf milevamde. Sedegi miRebuli iyo kvaziklasikurmiaxloebaSi, romelsac mivyavarT kvanturi dinamiuri sistemisSemoklebuli aRweris SesaZleblobaze (fazur sivrceSi) <strong>da</strong> rogorc Sedegi- napovni iyo paulis saxis kinetikuri gantoleba.ukanasknel wlebSi, dinamiuri sistemebis TeoriaSi, farTo ganviTarebahpova mkacrma meTodebma kvanturi dinamiuri qvesistemis dinamikisaRwerisa, romelic urTierTqmedebs <strong>da</strong>kvantul bozonur velTan(TermostatTan). es meTodebi gamoirCeva im TaviseburebiT, rom saSualebasiZleva, raTa miRebuli iqnas Tanafardobebi, romlebic aRweren qvesistemisdinamikas, romelic samarTliania bozonur velTan urTierTqmedebis (bmis)mudmivas nebismieri mniSvnelobebis dros, nebismieri temperaturebisa <strong>da</strong> nebismierigareSe moqmedi Zalebis SemTxvevaSi. am midgomebis dros argamoiyeneba <strong>da</strong>Sveba mTeli dinamiuri sistemis statistikuri operatorisgamartivebis Sesaxeb didi droebis SemTxvevaSi: t >>τ0(sa<strong>da</strong>c: τ0-warmoadgens qaotizaciis maxasiaTebel dros), rodesac am <strong>da</strong>SvebisTanaxmad, mTeli kvanturi dinamiuri sistemis statistikuri operatorixdeba qvesistemis <strong>da</strong>yvanili (reducirebuli) statistikuri operatorisfunqcionali.pirvelad aseTi saxis evoluciuri gantoleba qvesistemis statistikurioperatorisaTvis, rodesac qvesistema urTierTqmedebs bozonurvelTan (fononebTan), romlebic imyofebian statistikuri wonasworobismdgomareobaSi T temperaturiT, miRebuli iyo [15-16] naSromebSi, bozonuriamplitudebis zusti gamoricxviT am evoluciuri gantolebi<strong>da</strong>n.evoluciuri gantoleba Sfm-is gamoyenebiT qvesistemis statistikurioperatorisTvis, romelic urTierTqmedebs TermostatTan, miRebuli iyo [67-71] SromebSi, romelic gansxvavebiT [5-6, 14-16] naSromebSi miRebuligantolebebisagan aris Caketili. sivrculi erTgvarovnebis SemTxvevaSi,qvesistemis (eleqtronis) TermostatTan susti urTierTqmedebis dros68


SeSfoTebis Teoriis meore miaxloebaSi am evoluciuri gantolebi<strong>da</strong>ngamomdinareobs bolcmanis gantoleba eleqtronisaTvis [57,69-71].ganzogadoebuli kvanturi kinetikuri gantolebebis mkacri gamoyvanaeleqtron-fononuri sistemisaTvis Sesrulebuli iyo [6,14-15] SromebSi,sa<strong>da</strong>c ganxiluli iyo agreTve am gantolebebis gamoyeneba sxva<strong>da</strong>sxvamodelisTvis. Seqmnili iyo meTodi kinetikuri gantolebebis miRebisa,romelic eyrdnobo<strong>da</strong> ganviTarebul specifiur teqnikas – velis kvanturiTeoriisa <strong>da</strong> T-namravlTa formalizmis <strong>da</strong>xmarebiT, – bozonuri amplitudebisgamoricxvisa Sesabamisi kinetikuri gantolebebi<strong>da</strong>n [5-6]. Sesabamisimiaxloebebis SesrulebiT, gamoyvanili kinetikuri gantolebebi<strong>da</strong>nmiRebuli iyo konkretuli fizikuri Sedegebi, romlebic aRweren eleqtronisa<strong>da</strong> polaronis kinetikas [27,29-31,38]. amrigad, fun<strong>da</strong>menturi midgoma,romelic ganviTarebuli <strong>da</strong> gamoyenebuli iyo [14-15] SromebSi, saSualebasiZleo<strong>da</strong> Sfm-Si ganzogadoebuli kvanturi evoluciuri gantolebebismiRebas sistemis statistikuri operatorisTvis, gamoricxuli bozonuriamplitudebiT.ukanasknel periodSi, arawonasworuli <strong>da</strong> Seuqcevadi procesebisaRsawerad <strong>da</strong> Sesabamisi adekvaturi Teoriis Sesaqmnelad, myari sxeulebisfizikaSi farTo gamoyeneba <strong>da</strong> ganviTareba hpova arawonasworuli statistikurimeqanikis sxva<strong>da</strong>sxva meTodebma. arawonasworul sistemebSirelaqsaciuri procesebis Sesaswavlad didi mniSvneloba eniWebakorelaciuri <strong>da</strong> grinis funqciebis meTods [4,34,64-65,72-73]. ukanasknelwlebSi, arawonasworuli movlenebis gamosakvlevad xSirad gamoiyenebaagreTve proeqciuli operatoris meTodi [74]. Gganzogadoebuli kvanturikinetikuri gantoleba statistikuri operatorisaTvis qvesistemisa,romelic urTierTqmedebs bozonur TermostatTan, SesaZlebelia miRebuliqnas aseve arawonasworuli statistikuri operatoris meTodis gamoyenebiT[4,34].[68] naSromSi, proeqciuli operatorisa <strong>da</strong> grinis superoperatorismeTodi gamoiyenebo<strong>da</strong> Caketili evoluciuri gantolebis misaRebadqvesistemis statistikuri operatorisaTvis, romelic urTierTqmedeb<strong>da</strong>bozonur velTan, sai<strong>da</strong>nac gamoricxuli iyo bozonuri operatorebi. amnaSromSi, liuvilis superoperatoruli formalizmisa <strong>da</strong> proeqciulioperatoris meTodis <strong>da</strong>xmarebiT, gamoyvanili iyo moZraobis ganzo-69


gadoebuli, kvanturi gantoleba grinis <strong>da</strong>gvianebuli superoperatorisTvis.grinis superoperatorebis meTodi gamoiyenebo<strong>da</strong> agreTve [75-76] naSromebSi,sa<strong>da</strong>c miRebuli iyo kvanturi evoluciuri gantolebebi qvesistemisoperatorebis drois ormomentiani wonasworuli korelaciurifunqciebisTvis. Sesabamisi miaxloebebis ganxilvisas qvesistemis(eleqtronis) dinamikisTvis, am gantolebebi<strong>da</strong>n martivad miiRebo<strong>da</strong>cnobili Sedegebi eleqtron-fononuri sistemisTvis <strong>da</strong>, kerZod polaroniskinetikaSi [29,77]; magram, miuxe<strong>da</strong>vad amisa, xazi un<strong>da</strong> gaesvas im garemoebas,rom yvela zemoT moyvanil naSromSi, qvesistemis statistikuri operatoris-Tvis ganzogadoebuli kvanturi evoluciuri gantolebis gamoyvanisas, <strong>da</strong>grinis superoperatorebisTvis moZraobis gantolebebis miRebisas, gamoiyenebo<strong>da</strong>aproqsimacia – Sfm, <strong>da</strong> amitom am naSromebSi yvela miRebuligantoleba – rogorc qvesistemis statistikuri operatorisTvis, iseqvesistemis operatorebis wonasworuli korelaciuri funqciebisTvis – araris zusti.rogorc cnobilia, wrfivi ga<strong>da</strong>tanis movlenebis Sesaswavlad myarsxeulebSi, erT-erT efeqtur xerxs warmoadgens meTodi, romelic<strong>da</strong>myarebulia bolcmanis kinetikuri gantolebis gamoyenebaze. Gga<strong>da</strong>tanismovlenebis kvanturi Teoria, romlis aRsawerad gamoiyeneba bolcmanisgantoleba, faqtiurad warmoadgens kvaziklasikur Teorias, romelic<strong>da</strong>fuZnebulia adiabatur miaxloebasa <strong>da</strong> SeSfoTebis Teoriaze.eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis kvantur TeoriaSibolcmaniseuli midgomisas igulisxmeba, rom gamtarobis eleqtronebi (anpolaronebi) imyofebian stacionarul <strong>da</strong> TiTqmis “Tavisufal” mdgomareobebSikvaziimpulsebis gansazRvruli mniSvnelobebiT. kristaluri mesrisperiodulobis <strong>da</strong>rRveva ganpirobebuli, magaliTad fononebiT, iwvevs<strong>eleqtronebis</strong> mdgomareobaTa arastacionarobas. <strong>eleqtronebis</strong> fononebzegabnevisas igulisxmeba, rom gabnevis procesebis aqtebi kargad aris gancalkevebulisivrcesa <strong>da</strong> droSi, <strong>da</strong> amitom, faqtiurad, adgili ar aqvsinterferenciis movlenas <strong>eleqtronebis</strong> erTi mdgomareobi<strong>da</strong>n meoreSiga<strong>da</strong>svlis dros. kristalze modebuli gareSe eleqtruli veli ganixilebarogorc susti intensivobisa (mcire amplitudebis mqone) <strong>da</strong> mdored cvladisivrcesa <strong>da</strong> droSi. rogorc Sedegi, aseTi gareSe eleqtruli velismoqmedeba iwvevs mxolod muxtis matarebelTa aCqarebas <strong>da</strong> maT ga<strong>da</strong>svlebs70


sxva<strong>da</strong>sxva mdgomareobebSi ise, rom ar xdeba TviT am mdgomareobebisarsebiTi cvlileba. aseT SemTxvevebSi eleqtronis gabnevis kveTebi ariReben did mniSvnelobebs. amgvarad, bolcmaniseuli aRwera SeiZleba CaiTvalosrogorc kvaziklasikuri, specifiuri kvantur-meqanikuri efeqtebisgareSe.eleqtron-fononuri sistemisaTvis bolcmanis ganzogadoebuligantoleba <strong>da</strong> polaronis frolixis modelisaTvis bolcmanis gantolebamiRebuli iyo susti eleqtron-fononuri urTierTqmedebis SemTxvevaSi [14-15] naSromebSi. bolcmanis gantolebis miRebisa <strong>da</strong> gamoyenebissafuZvlianoba <strong>eleqtronebis</strong> drekadi gabnevis SemTxvevaSi minarevulcentrebze, rodesac es ukanasknelni ganlagebulni arian qaosuradsivrceSi, ganxiluli iyo [78-79] naSromebSi. rogorc ukve aRvniSneT,bolcmanis gantoleba SesaZlebelia miRebuli iqnas agreTve qvesistemis(eleqtronis) simkvrivis matricis zusti, Caketili kinetikurigantolebi<strong>da</strong>n, rodesac adgili aqvs eleqtronis sust urTierTqmedebaspolarul optikur fononebTan, romelic ganxiluli iyo [67,69-71]naSromebSi. magram miuxe<strong>da</strong>vad amisa un<strong>da</strong> aRiniSnos, rom ga<strong>da</strong>tanismovlenebis wrfiv TeoriaSi, ga<strong>da</strong>tanis meqanikuri koeficientebisgamosaTvlelad bolcmanis kinetikuri gantolebis gamoyenebis areSezRudulia. ase magaliTad, eleqtron-fononuri sistemis SemTxvevaSi, Tu<strong>eleqtronebis</strong> fononebze gabnevis sxva<strong>da</strong>sxva aqtebi erTmaneTTan ganicdianinterferencias, maSin cxadia, rom bolcmanis kinetikuri gantoleba ukvear gamoiyeneba [80].gasuli saukunis 70-ian wlebSi, ga<strong>da</strong>tanis arawrfivi movlenebis aRsawerad<strong>da</strong> meqanikuri koeficientebis (mag. Zvradoba) gamosaTvlelad,tornbergisa <strong>da</strong> feinmanis mier ganviTarebuli iyo axali midgoma, romelicTavisufali iyo im SezRudvebisagan rasac moicav<strong>da</strong> ga<strong>da</strong>tanis movlenebisbolcmaniseuli aRwera. gamoyenebul iqna ra kontinualuri integrebismeTodi, tornbergisa <strong>da</strong> feinmanis mier <strong>da</strong>dgenili iyo arawrfivi<strong>da</strong>mokidebuleba kristalze modebul gareSe eleqtrul velsa <strong>da</strong> muxtismatareblis (eleqtronis) <strong>da</strong>myarebul saSualo siCqares Soris polarulnivTierebebSi [84]. tornberg-feinmanis Teoriis sqemaSi eleqtron-fononurisistemis statistikuri operatorisTvis, romelic ganisazRvrebo<strong>da</strong> liuvilfonneimanis evoluciuri gantolebi<strong>da</strong>n, gamoyenebuli iyo Zalian rTuli71


maTematikuri formalizmi <strong>da</strong>fuZnebuli feinmanis integralebzetraeqtoriebis gaswvriv [53,84]. un<strong>da</strong> aRiniSnos, rom feinmanistraeqtoriebiT integralebis gamoTvla ar xerxdebo<strong>da</strong> zustad <strong>da</strong> amitomzemoTmiTiTebuli avtorebi iyenebdnen sxva<strong>da</strong>sxva miaxloebebs fizikuriSedegebis misaRebad. am midgomis farglebSi, eleqtron-fononuri sistemissimkvrivis matrici<strong>da</strong>n xdebo<strong>da</strong> fononuri operatorebis gamoricxva.amgvarad, tornberg-feinmanis midgoma <strong>da</strong> meTodi amyareb<strong>da</strong> arawrfivTanafardobas gareSe sasrul (Zlier) eleqtrul velebsa <strong>da</strong> eleqtronissaSualo siCqareebs Soris polarul kristalSi, rac faqtiuradsaSualebas iZleo<strong>da</strong> myar sxeulebSi ga<strong>da</strong>tanis arawrfivi movlenebisSeswavlis SesaZleblobas [84-85]. xazi un<strong>da</strong> gaesvas im garemoebas, romtornberg-feinmanis mier miRebuli zemoTnaxsenebi Sedegebi samarTlianiarogorc Zlieri, aseve susti eleqtron-fononuri urTierTqmedebisSemTxvevaSi. samecniero literaturaSi tornberg-feinmanis midgoma cnobiliarogorc balansis gantolebis meTodi. aqve un<strong>da</strong> aRvniSnoT, rombalansis gantolebis meTodi awydeba siZneleebs eleqtronis (an polaronis)Zvradobis gamoTvlisas polarul nivTierebebSi Zalian <strong>da</strong>balitemperaturebis dros. am meTodSi miCneulia, rom arc Tu ise Zlierieleqtruli velebisas miiRweva stacionaruli mdgomareoba, rodesaceleqtroni moZraobs mudmivi siCqariT. [84] naSromSi <strong>da</strong>xatuli fizikurisuraTi, eleqtronis <strong>da</strong>myarebuli siCqaris <strong>da</strong>mokidebulebisa Zlierstatikur eleqtrul velze, principSi samarTliania α, T <strong>da</strong> E-s nebismierimniSvnelobebisaTvis, magram avtorebi aRniSnaven or ZiriTad sirTules,romelic jer kidev ar aris ga<strong>da</strong>laxuli dRevandel dRemde:1) impulsis balansis gantolebaze <strong>da</strong>yrdnobiT miRebuli Sedegebi aremTxveva im Sedegebs, romlebic miiReba energiis balansis gantolebi<strong>da</strong>n.2) susti intesivobis eleqtruli velebis SemTxvevaSi, ZvradobagamoTvlili balansis gantolebis <strong>da</strong>xmarebiT ar emTxveva Zvradobis immniSvnelobas, romelic miiReba bolcmanis gantolebis amoxsniT (gansxvavdebamisgan3 KBT-faqtoriT).2 hω0rogorc mogvianebiT gairkva [15-16], tornbergisa <strong>da</strong> feinmanis TeoriisSedegi (mxolod susti eleqtron-fononuri urTierTqmedebis zRvrulSemTxvevaSi) SeiZleba miviRoT bolcmanis gantolebi<strong>da</strong>n, Tu vivaraudebT,72


om mis stacionarul amoxsnas aqvs kvazimaqsvelis ganawilebis funqciissaxe. marTlac, erTis mxriv eleqtron-fononuri sistemis qmedebisaproqsimacias kvadratuli funqcionaliT (feinmanis meTodSi – integralebitraeqtoriebis gaswvriv) yovelTvis mivyavarT kvazimaqsvelis tipisimpulsis ganawilebis funqciasTan [53,85] <strong>da</strong> amave dros, meores mxrivbolcmanis gantolebis amonaxsnTa gamokvlevebi [86] <strong>da</strong> eleqtronis dreifulisiCqaris gamoTvlis eqsperimentaluri monacemebi Zlier eleqtrulvelebSi <strong>da</strong>bali temperaturebisas [87] cxa<strong>da</strong>d gviCveneben, rom impulsisganawilebis funqcia mkveTrad gansxvavdeba maqsveliseulisagan.Tvisobrivad es <strong>da</strong>kavSirebulia im faqtTan, rom <strong>da</strong>bali temperaturebisa<strong>da</strong> Zlieri velebis SemTxvevaSi, relaqsaciis dominirebul meqanizmadgvevlineba polaruli optikuri fononebis gamosxiveba, romelic arisZlier aradrekadi <strong>da</strong> anizotropuli xasiaTis procesi <strong>da</strong> romelsacmivyavarT denis matareblebis specifiur yofaqcevamde, romelic cnobilia,rogorc “Streaming motion” movlena. miuxe<strong>da</strong>vad zemoT aRniSnuli sir-Tuleebisa, [84-85] naSromebSi mocemuli Teoria warmoadgens jerjerobiTerTaderT mikroskopul Teorias eleqtronisa, nebismieri eleqtronfononuriurTierTqmedebis SemTxvevaSi Zlier gareSe eleqtrul velSi.imisaTvis, rom <strong>da</strong>eZliaT eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanismovlenebis siZneleebi naxevargamtarebsa <strong>da</strong> ionur kristalebSi, romlebic<strong>da</strong>fuZnebuli iyo bolcmanis gantolebis gamoyenebaze, <strong>da</strong> im mizniT, romaegoT impen<strong>da</strong>nsis erTiani wrfivi Teoria polaronisTvis (eleqtronisTvis)gareSe eleqtruli velis nebismieri sixSireebis, kristalis nebismieritemperaturebisa <strong>da</strong> eleqtron-fononuri bmis mudmivas nebismieri mniSvnelobisdros, feinmanis, xelvorsis, idingsisa <strong>da</strong> platcmanis (fxip) mierganviTarebuli iyo midgoma, romelic <strong>da</strong>fuZnebuli iyo eleqtron-fononurisistemisTvis arawonasworuli simkvrivis matricis gamoTvlaze feinmanismeTodiT – integralebi traeqtoriebis gaswvriv. fxip-is mier miRebuli iyowrfivi gamoZaxilis funqciis zusti mniSvneloba ormagi kontinualuriintegralis saxiT traeqtoriebis gaswvriv, romelic Semdeg aproqsimirebuliiyo feinmanis erToscilatoriani modelis farglebSi [88]. fxip-ismidgomam Semdgomi ganviTareba hpova [47,89-90] SromebSi. fxip-is miermiRebuli impen<strong>da</strong>nsis zogadi gamosaxulebi<strong>da</strong>n gamoyvanili iyo polaronisefeqturi masisTvis zogadi formula, napovni iyo polaronis optikuri73


STanTqmis koeficienti <strong>da</strong> sxv. miRebuli iyo agreTve polaronis Zvradobiszogadi formula bmis mudmivas nebismieri mniSvnelobisa <strong>da</strong> nebismieritemperaturis dros. un<strong>da</strong> aRiniSnos, rom fxip-is mier miRebuli yvelaSedegi samarTliania agreTve eleqtronisTvisac, bmis mudmivas mcire (α < 1)mniSvnelobebisas. magram miuxe<strong>da</strong>vad fxip-is midgomis universalobisa, ammidgomasac gaaCnia sirTuleebi, romlebic dRemde ar aris ga<strong>da</strong>wyvetili.erT-erTi ZiriTadi sirTule mdgomareobs imaSi, rom iseve rogorctornberg-feinmanis TeoriaSi, aqac napovni dreifuli ZvradobismniSvneloba kristalis <strong>da</strong>bali temperaturebis dros3 KBT-TanamamravliT2 hωgansxvavdeba Zvradobis im mniSvnelobisagan, romelic miiReba bolcmanisgantolebis amoxsniT <strong>da</strong>bali temperaturebisas <strong>da</strong> bmis mudmivas rogorcmcire, aseve didi mniSvnelobis dros. Aarawonasworuli simkvrivis matricismeTodis sirTule mdgomareobs agreTve imaSi, rom arsebobs garkveuliganusazRvreloba impen<strong>da</strong>nsis miaxloebiTi mniSvnelobis SerCevaSi,romelic aiReba maTematikurad aramkacri mosazrebebisa <strong>da</strong> fizikisTvalsazrisiT gonivruli aproqsimaciis ganxilvaSi. saerTo jamSi un<strong>da</strong>iTqvas, rom fxip-is mier napovni eleqtrogamtarobis tenzorisgamosaxuleba ZiriTa<strong>da</strong>d sworad <strong>da</strong> erTiani TvalsazrisiT misaReba<strong>da</strong>Rwers polaronul efeqtebs optikaSi, galvanomagnitur movlenebs <strong>da</strong>ciklotronul rezonans myari sxeulebis fizikaSi <strong>da</strong> sxv.rogorc ukve aRniSnuli iyo sadisertacio naSromis SesavalSi,eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis gamosakvlevadnaxevargamtarebsa <strong>da</strong> ionur kristalebSi, gar<strong>da</strong> bolcmanis kinetikurigantolebisa <strong>da</strong> zemoTmoyvanili midgomebisa <strong>da</strong> meTodebisa, SesaZlebeliagamoyenebuli iqnas sruliad gansxvavebuli (alternatiuli) midgoma,romelic <strong>da</strong>fuZnebulia kubos wrfivi gamoZaxilis Teoriaze [4,64,72-73]. ammidgomis farglebSi araviTari SezRudva ar edeba eleqtronis gabnevisaqtebs (gabnevis kveTebs) fononebze, gansxvavebiT bolcmaniseuliaRwerisagan. magram miuxe<strong>da</strong>vad amisa, eleqtrogamtarobis gamoTvlisaskubos meTodiT warmoiSveba sirTuleebi, romlebic <strong>da</strong>kavSirebulia ganSladobebTanσ(? )-eleqtrogamtarobis gaSlisas mwkrivad eleqtronisurTierTqmedebis hamiltonianis mixedviT fononebTan (gambnevebTan), gareSeeleqtruli velis <strong>da</strong>bali ? →0 – sixSireebis SemTxvevaSi. susti eleqtron-074


fononuri urTierTqmedebis SemTxvevaSic, σ(? )-eleqtrogamtarobisTvis sworiSedegis misaRebad, rodesac ? →0, aucilebelia ganSladi wevrebisganSedgenili usasrulo mwkrivis ajamva [80]. kubos wrfivi reaqciis Teoriam –eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis aRsawerad – SemdgomiganviTareba hpova [91,93-95] SromebSi. [91] naSromSi liuvilis gantolebaze<strong>da</strong>yrdnobiT <strong>da</strong> proeqciuli operatoris meTodis gamoyenebiT, eleqtronfononurisistemisTvis miRebuli iyo eleqtrowinaRobis zogadi formula.SeSfoTebis Teoriis gamoyenebiTa <strong>da</strong> Sesabamisi miaxloebebis ganxilviT(e.w. kenkre-drezdenis aproqsimacia) am zogadi gamosaxulebi<strong>da</strong>n napovni iyoeleqtrowinaRobis (impen<strong>da</strong>nsis) miaxloebiTi formula. mogvianebiT [101]-naSromSi naCvenebi iyo, rom kenkre-drezdenis aproqsimacia impen<strong>da</strong>nsisTvis<strong>da</strong> kubos formulisTvis ekvivalenturia fxip-is mier gamoyvaniliimpen<strong>da</strong>nsis (eleqtrowinaRobis) miaxloebiTi mniSvnelobisa sustieleqtron-fononuri urTierTqmedebis SemTxvevaSi. kubos wrfivigamoZaxilis Teoria <strong>da</strong> proeqciuli operatoris meTodi [94]-naSromSicgamoyenebuli iyo eleqtruli winaRobis Teoriis asagebad. miRebuli iyozogadi gamosaxuleba eleqtrowinaRobisTvis <strong>da</strong> naCvenebi iyo, rom iseverogorc eleqtrogamtarobisTvis, eleqtrowinaRobis swori mniSvnelobismisaRebad aucilebelia calkeuli wevrebisgan Sedgenili usasrulomwvrivis ajamva. zogadi saxiT <strong>da</strong>dgenili iyo martivi kavSiri kompleqsureleqtrogamtarobasa <strong>da</strong> impen<strong>da</strong>ns Soris. [95]-naSromSi kubos Teoriisa, fonneimanis gantolebisa <strong>da</strong> cvancigis tipis proeqciuli operatoris <strong>da</strong>xmarebiTmiRebuli iyo araerTgvarovani ZiriTadi kinetikuri gantoleba,romelic saSualebas iZleo<strong>da</strong> gamoZaxilis funqciis povnisa kubos formalizmSi.gamoyvanili iyo agreTve formulebi ganzogadoebuli amTviseblobisa<strong>da</strong> eleqtrogamtarobisTvis. ZiriTadi kinetikuri gantolebis<strong>da</strong>xmarebiT napovni iyo bolcmanis tipis gantoleba pirveli momentisTvis,romelic Seicav<strong>da</strong> rogorc disipaciur, aseve nakadisebr wevrebs.kubos formalizmi <strong>da</strong> grinis funqciaTa meTodi [83], [93] naSromSigamoyenebuli iyo polaronis <strong>da</strong>baltemperaturuli Zvradobis gamosaTvleladSeSfoTebis Teoriis meoTxe miaxloebaSi. avtorTa mier amnaSromSi, eleqtronis siCqaris drois ormomentiani korelaciuri funqciagamosaxuli iqna grinis ornawilakovani funqciis saSualebiT, xologrinis ornawilakovani funqcia warmodgenili iqna grinis erTnawilakovani75


funqciisa <strong>da</strong> eleqtron-fononuri urTierTqmedebis mixedviT mwkrivissaxiT. sabolood, maT mier napovni <strong>da</strong>baltemperaturuli Zvradobis mniSvnelobaiZleo<strong>da</strong> karg miaxloebas [55]-naSromSi miRebul polaronis<strong>da</strong>baltemperaturuli Zvradobis sididesTan, rodesac α


fononebze, e.w. polaronis rezonansuli urTierTqmedeba (gabneva)fononebTan, <strong>da</strong> am procesis gaTvaliswinebiTa <strong>da</strong> bolcmanis gantolebisamoxsniT, napovni iyo <strong>da</strong>baltemperaturuli Zvradobis mniSvnelobapolaronisTvis. [52]- naSromSi, polaronis Zvradoba feinmanis modelSigamoTvlili iyo sasruli temperaturebisa <strong>da</strong> arasusti eleqtron-fononuribmis SemTxvevaSi. [52]- naSromi faqtiurad warmoadgen<strong>da</strong> [51,55-56]Sromebis (osakas Sedegebis) ganzogadoebas – oRond gansxvavebiT yvelasxva zemoT miTiTebuli naSromebisgan, am naSromSi bolcmanis gantolebaamoxsnili iyo variaciuli meTodis gamoyenebiT (zemoTaRniSnul SromebSibolcmanis gantolebis amosaxsnelad ZiriTa<strong>da</strong>d gamoiyenebo<strong>da</strong> relaqsaciisdrois miaxloeba, an am meTodis esa Tu is modificirebuli forma).ricxviTi gamoTvlebi Catarebuli iyo TIBr-kristalebis nimuSTa monacemebismixedviT <strong>da</strong> karg TanxvedraSi iyo eqsperimentis SedegebTan. aqve un<strong>da</strong>aRiniSnos, rom zemoTmoyvanil naSromebSi <strong>da</strong> saerTod kinetikurigantolebis meTodSi, bolcmanis gantolebis amoxsnisas (saubariagawrfivebul gantolebaze) gamoiyeneba sxva<strong>da</strong>sxva saxis miaxloebebi (ix.mag. [106]), <strong>da</strong> amitom eleqtronis <strong>da</strong> polaronis <strong>da</strong>baltemperaturuliZvradobebisTvis miRebuli mniSvnelobebi ar aris Tanmimdevruli <strong>da</strong> zusti.zoga<strong>da</strong>d Zalian rTulia mkafiod <strong>da</strong>dgindes bolcmaniseuli midgomisgamoyenebis sazRvrebi saSualo <strong>da</strong> Zlieri eleqtron-fononuri bmisSemTxvevebSi. mosalodnelia, rom es midgoma samarTliani iqneba kristalis<strong>da</strong>bali temperaturebis dros, rodesac <strong>da</strong>jaxebaTa xangrZlivobis dro(romelic aris hβ= h KBT-s rigis) bevrad naklebia t-relaqsaciis droze.variaciuli meTodi [106]- bolcmanis kinetikuri gantolebis amosaxsneladpolaronis frolixis modelSi ganixilebo<strong>da</strong> agreTve [99]- naSromSi.gamoTvlili iyo frolixis polaronis <strong>da</strong>baltemperaturuli dreifuliZvradobis sidide, romelic emTxveo<strong>da</strong> relaqsaciis drois miaxloebaSifrolixis mier napovn <strong>da</strong>baltemperaturuli statikuri ZvradobismniSvnelobas polaronisTvis [43]. amrigad, rogorc zemoTmoyvanilinaSromebis mimoxilva gviCvenebs, arsebobs arsebiTi gansxvaveba polaronisZvradobis mniSvnelobebs Soris, romelic erTis mxriv miiReba bolcmanisgantolebis amoxsnisas relaqsaciis drois miaxloebaSi <strong>da</strong> meores mxrivfeinmanis meTodis – integralebi traeqtoriebis gaswvriv gamoyenebisaspolaronis frolixisa <strong>da</strong> feinmanis modelebSi [100]. susti gareSe77


eleqtruli velebisa <strong>da</strong> susti eleqtron-fononuri bmis SemTxvevaSi,polaronis Zvradobis gamoTvlisas relaqsaciis drois miaxloebaSe<strong>da</strong>rebiT ufro realuri Cans, vidre balansis gantolebis meTodi [84-85,100]. [84,88] -naSromebSi polaronis Zvradoba gamoTvlili iyo feinmanismeTodiT – integralebi traeqtoriebis gaswvriv, xolo [15,85,101] SromebSiZvradobis gamoTvlisas gamoiyenebo<strong>da</strong> eleqtronis impulsebis mixedviT maqsveliswanacvlebuli ganawilebis funqcia. [101] - naSromSi naCvenebi iyo,rom meTodebi romlebic ganviTarebuli <strong>da</strong> gamoyenebuli iyo [91-92,84,88]SromebSi, susti eleqtron-fononuri bmisa <strong>da</strong> susti gareSe eleqtrulivelebis SemTxvevaSi, polaronis <strong>da</strong>baltemperaturuli ZvradobisTvis iZleodnenfaqtiurad erTnair mniSvnelobebs; rac Seexeba gamoTvlebs, romlebic<strong>da</strong>fuZnebulia bolcmanis kinetikuri gantolebis gamoyenebaze,optikuri polaronis <strong>da</strong>baltemperaturuli dreifuli ZvradobisTvismivyavarT sxva mniSvnelobebTan. [97,100]. kritikuli analizi, polaronisZvradobisTvis miRebuli sxva<strong>da</strong>sxva mniSvnelobebis Tanxvdenis Sesaxeb,Catarebuli iyo [102,103]- SromebSi, <strong>da</strong> <strong>da</strong>dgenili iyo, rom optikuri polaronisZvradobis sidide <strong>da</strong>mokidebulia zRvruli ga<strong>da</strong>svlebis α→0, ? →0operaciebis Tanmimdevrobaze (am SromebSi naCvenebi iyo, rom zRvruliga<strong>da</strong>svlebis swori Tanmimdevrobaa:limlim ).α→0ω→ 0polaronis fgm-Si[57-58]-bolcmanis tipis kinetikuri gantolebaZlieri eleqtron-fononuri bmisa <strong>da</strong> kristalis <strong>da</strong>bali temperaturebisSemTxvevaSi, miRebuli iyo [70-71]- SromebSi. bolcmanis gantolebismiRebisas, avtorebi eyrdnobodnen maT mier [68-69]- naSromebSi gamoyvanilCaketil kinetikur gantolebas qvesistemis (polaronis) statistikurioperatorisaTvis, romelic napovni iyo Sfm-Si. Gganixilebo<strong>da</strong> mciresiCqariT moZravi polaroni <strong>da</strong>bali temperaturebis dros <strong>da</strong> miRebuli iyokinetikuri gantoleba qvesistemis statistikuri operatoris, rogorcdiagonaluri matriculi elementisaTvis (polaronis ganawilebisfunqciisTvis, polaronis ZiriTadi mdgomareobisTvis), asevearadiagonaluri matriculi elementebisaTvis (polaronis agznebuli,ga<strong>da</strong>gvarebuli mdgomareobebisTvis). rac Seexeba TviT sakuTriv polaronisZvradobas, igi gamoTvlili ar iyo am modelSi. aqve, erTxel kidev un<strong>da</strong>aRiniSnos <strong>da</strong> xazi gaesvas im garemoebas, rom TviT bolcmanis kinetikurigantolebis sxva<strong>da</strong>sxva meTodebiT gamoyvanisas <strong>da</strong> misi amoxsnisas gamo-78


iyeneba sxva<strong>da</strong>sxva saxis miaxloebebi, <strong>da</strong> amitom eleqtronis <strong>da</strong> polaronisZvradobis Tanmimdevruli <strong>da</strong> koreqtuli gamoTvlis problema sxva<strong>da</strong>sxvamodelSi moiTxovs Semdgomi <strong>da</strong>matebiTi gamokvlevebis Catarebas.kovalentur (araionur) kristalebSi, magaliTad germaniumisa <strong>da</strong>siliciumis tipis naxevargamtarebSi, <strong>eleqtronebis</strong> urTierTqmedebafononebTan aRiwereba deformaciis potencialis meTodiT, romelicmoqmedebs zonur eleqtronze <strong>da</strong> romelic warmoadgens axlomqmedSeSfoTebas kristalis perioduli potencialisTvis [39,42,107]. eleqtronismoZraobis SeSfoTeba, gamowveuli am urTierTqmedebiT, warmoadgenskvazinawilakis gabnevas deformaciis potencialze. Tavisi bunebi<strong>da</strong>ngamomdinare, es urTierTqmedeba <strong>da</strong>maxasiaTebelia yvela naxevargamtarebis-Tvis <strong>da</strong> saerTod myari sxeulebisTvis. rogorc cnobilia, eleqtronisurTierTqmedeba (gabneva) akustikur fononebTan SesaZlebelia iyos rogorcsusti, aseve Zlieri [41,104]. eleqtronis susti urTierTqmedebisasakustikur fononebTan, eleqtronis ga<strong>da</strong>adgilebas kovalenturi kristalebisgamtarobis zonaSi Tan axlavs kristalis lokaluri deformaciisga<strong>da</strong>nacvleba, romelic aRiwereba SeSfoTebis Teoriis enaze, rogorceleqtronis mier virtualuri fononebis gamosxivebisa <strong>da</strong> STanTqmisprocesi; xolo kristalebSi, romlebsac gaaCniaT mcire drekadobismodulebi <strong>da</strong> gamtarobis zonaSi <strong>eleqtronebis</strong> didi efeqturi masebi –eleqtronis urTierTqmedeba grZiv akustikur fononebTan aris Zlieri,rasac mivyavarT kristalis lokalur deformaciasTan, romelic sakmarisiapotencialuri ormos warmosaqmnelad <strong>da</strong> romelSiac eleqtroni asrulebsstacionarul moZraobas diskretuli energiiT (e.w. akustikuri polaronismodeli) [39,41-42,104-105]. Aakustikuri polaronis modelTan, <strong>da</strong> saerTodkvazinawilakis lokalizaciis problemasTan myar sxeulebSi, mWidrod aris<strong>da</strong>kavSirebuli sakiTxi eleqtronis e.w. TviTCaWerisa, romelic gamowveuliaZlieri eleqtron-fononuri urTierTqmedebiT [41-42,104-105]. akustikuripolaronis modeli – feinmanis meTodiT, integralebi traeqtoriebis gaswvriv– Seswavlili iyo [41,104-105] SromebSi. <strong>da</strong>dgenili iyo, rom Zlierieleqtron-fononuri bmis SemTxvevaSi adgili aqvs eleqtronis TviTCaWeras,romelic ganpirobebulia deformaciis potencialiT gamowveuli axlomqmediurTierTqmedebiT. saerTod un<strong>da</strong> aRiniSnos, rom <strong>eleqtronebis</strong>TviTCaWeris amocanis Seswavlas didi mniSvneloba aqvs eleqtronuli79


(polaronuli) ga<strong>da</strong>tanis movlenebis aRsawerad myar sxeulebSi, vinai<strong>da</strong>nkristaluri mesris deformaciis Sedegad TviTCaWerili kvazinawilaki ariZleva wvlils eleqtrogamtarobaSi (ZvradobaSi).susti eleqtron-fononuri bmis SemTxvevaSi, eleqtronuli ga<strong>da</strong>tanismovlenebis Sesaswavlad akustikuri polaronis modelSi kristalis<strong>da</strong>bali temperaturebis dros, gamoiyeneba kinetikuri (bolcmanis) gantolebismeTodi. <strong>da</strong>bali temperaturebisas eleqtronis Zvradoba ZiriTa<strong>da</strong>dganisazRvreba misi gabneviT kristalSi arsebul minarevebze <strong>da</strong> akustikurfononebze. sufTa kristalebSi <strong>da</strong>bali temperaturebisas- rodesacoptikuri fononebi sustad arian aRgznebuli – dominirebs eleqtronisgabneva akustikur fononebze. eleqtronis urTierTqmedebis energia grZeltalRovangrZiv akustikur fononebTan mcire sididisaa, vidre misiurTierTqmedebis energia polarul optikur fononebTan <strong>da</strong>, gar<strong>da</strong> amisa,eleqtronis energiis cvlileba akustikur fononebze gabnevisas,warmoadgens mcire sidides (kvazidrekadi gabneva). amis gamo, eleqtronisgabneva akustikur fononebze SesaZlebelia ganxilul iqnas relaqsaciisdrois miaxloebaSi [29,32-33,107]. vinai<strong>da</strong>n am SemTxvevaSic bolcmaniskinetikuri gantolebis amoxsnisas gamoiyeneba sxva<strong>da</strong>sxva saxis miaxloeba(magaliTad, Sfm), eleqtronis Zvradobis gamoTvla mis akustikurfononebze gabnevisas, moiTxovs <strong>da</strong>matebiTi gamokvlevebis Catarebas [29,108].sadisertacio naSromSi ganviTarebulia <strong>da</strong> gamoyenebulia midgoma,eleqtronuli <strong>da</strong> polaronuli ga<strong>da</strong>tanis movlenebis gamosakvlevadkvanturi dinamiuri sistemebis zemoTmoyvanili modelebisTvis (romlebicurTierTqmedeben fononur velTan), romelic <strong>da</strong>myarebulia kubos wrfivigamoZaxilisa <strong>da</strong> SeSfoTebis Teoriaze [109-122, 125].mowesrigebul operatorTa formalizmi <strong>da</strong> proeqciuli operatorismeTodi, T-namravlTa meTodi (teqnika) <strong>da</strong> fononuri (bozonuri) operatorebisgamoricxvis procedura wonasworuli, droiTi korelaciurifunqciebisaTvis aRwerili <strong>da</strong> gamoyenebuli iqneba sadisertacio naSromisII <strong>da</strong> III TavSi. III TavSi ganxilulia eleqtronuli <strong>da</strong> polaronuliga<strong>da</strong>tanis movlenebis sakiTxebi kvantur disipaciur sistemebSi –eleqtron-fononur sistemaSi, polaronis frolixis modelSi, akustikuripolaronis modelSi, polaronis fgm-Si– <strong>da</strong>fuZnebuli kubos wrfivi gamoZaxilisTeoriaze; kerZod, III TavSi gamoTvlilia eleqtronuli <strong>da</strong> po-80


laronuli ga<strong>da</strong>tanis meqanikuri (kinetikuri) koeficientebi (Zvradoba,eleqtrogamtaroba) zemoT miTiTebul modelebSi, zemoT naxseneb formalizmsa<strong>da</strong> meTodze, <strong>da</strong> korelaciuri funqciebisaTvis ganzogadoebulkvantur kinetikur gantolebebze <strong>da</strong>yrdnobiT.81


Tavi II. ganzogadoebuli kvanturi evoluciuri gantolebebidroisormomentiani wonasworuli korelaciuri funqciebisa <strong>da</strong> grinisfunqciebisTvis dinamiuri qvesistemisa, romelic urTierTqmedebsTermostatTan (bozonur velTan)2.1. mowesrigebul operatorTa formalizmi<strong>da</strong> T- namravlTa meTodiganvixiloT mcire dinamiuri qvesistema s, romelic urTierTqmedebsbozonur (fononur) velTan S. mTliani (s + S) sistemis hamiltoniani aviRoTSemdegi saxiT:sa<strong>da</strong>cH = H + H + H , (2.1)sΣint.Hsaris s qvesistemis sakuTari hamiltoniani; H Σ- warmoadgensbozonuri (fononuri) velis hamiltonians; xolourTierTqmedebis hamiltoniani – bozonur velTan.H+C ( s ) <strong>da</strong> C ( s)k= +Σ ∑ h ω ( kbb ) ; k k = ⎡ ( ) + ( )kk+ +∑ ⎣ k k k kkHint.- aris s qvesistemisH ⎤int.C s b C s b ⎦, (2.2)– warmoadgenen operatorebs, romlebic miekuTvnebian sqvesistemas. mTliani (2.1) – hamiltoniani ar aris <strong>da</strong>mokidebuli droze.A , B .... aRvniSnoT operatorebi Sredingeris warmodgenaSi, romlebicss<strong>da</strong>mokidebuli arian mxolod s qvesistemis dinamiur cvladebze <strong>da</strong>romlebic ar arian <strong>da</strong>mokidebuli droze. operatorebi, romlebic<strong>da</strong>mokidebuli arian mxolod s-is an S-s cvladebze, komutirebenerTmaneTTan. bozonuri (fononuri) sistema S ganixileba rogorcTermostati. <strong>da</strong>vuSvaT, rom As() t <strong>da</strong> Bs() t – warmoadgenen s qvesistemisoperatorebs haizenbergis warmodgenaSi:A ( t)= eSiHthA eS−iHth;SiHτhS−iHτhB ( τ ) = e B e ;am operatorebis sawyisi mniSvnelobebisaTvis gveqnebaAs = As() t , B ( )t=0 s= Bsττ = 0drois ormomentiani wonasworuli korelaciuri funqciebi <strong>da</strong> grinisfunqciebi (<strong>da</strong>gvianebuli, winmswrebi <strong>da</strong> mizezobrivi) ganisazRvrebianSemdegi tolobebiT (ix. mag. [25,34,64]).F ( t− τ) =< A () t B ( τ)>.AB s ss s82


a− τ = θ − τ < [ τ ] >; ( τ) θτ ( ) [ () ( τ )]rG ( t ) ( t ) As() t Bs( )ηG t− =− − t < Ast Bs>ηsa<strong>da</strong>c:⎧1; x > 0θ( x)= ⎨⎩0; x < 0c 1G ( t− τ) = < Tη{ AtBs() s( τ)} > , (2.3)ih{ }; [ ]A () t B ( τ) = A () t B ( τ) − ηB ( τ) A () t ;s s η s s s sTη As() t Bs( τ) = θ ( t− τ) As() t Bs() τ + ηθ( τ −tB )s( τ ) As()t .η = 1 - boze operatorebisaTvis <strong>da</strong> η =−1Ffermi operatorebisaTvis, <strong>da</strong>< ... >= Z( β ) SP s( e−1 −βH∑...);β kT, (2.4)− 1= B−βHsa<strong>da</strong>c: Z(β ) = SP s( e ) - warmoadgens statjams mTeli (s + S) sistemisaTvis; k B∑- aris bolcmanis mudmiva; T - absoluturi temperatura, xolo h –plankismudmiva; gasaSualoeba (2.4) formulaSi xorcieldeba gibsis kanonikuriansamblis wonasworuli statistikuri operatoris mixedviT.ganixileba Semdegi saxis zogadi amocana [109-113] – agebuli un<strong>da</strong>iqnas Teoria, romlis saSualebiTac SesaZlebeli iqneba miviRoT zusti,ganzogadoebuli (albaT araCaketili), kvanturi evoluciuri (kinetikuri)gantolebebi drois ormomentiani wonaworuli korelaciuri <strong>da</strong> grinisfunqciebisaTvisAs<strong>da</strong>Bs– operatorebisaTvis, s – dinamiuri qvesistemisaTvis,romelic urTierTqmedebs S sistemasTan – bozonur velTan. amTeoriis agebisas, gamoyenebuli un<strong>da</strong> iqnas mowesrigebul operatorTameTodi [5-6,59-61], (s + S) -sistemis (2.1) hamiltonianis cxadi saxe <strong>da</strong> gibsiskanonikuri ansamblis statistikuri operatori. gamoviyvanoT jerganzogadoebuli kvanturi, evoluciuri gantoleba wonasworulikorelaciuri funqciisaTvis:F () t =< B () t A >=< BA ( − t)>. (2.5)BA s ss s s s<strong>da</strong>smuli amocanis ga<strong>da</strong>sawyvetad CavweroT (2.5) korelaciuri funqciaSemdegi saxiT:−1 −βH−1< B () t A >= Z ( β) SΡ ⎡ () ⎤ = ( ) Ρ⎡ (, ) ⎤s s sΣ⎣e B t As s⎦ Z β S⎣AG t βs Bs⎦(2.6)(2.6) formulaSi, Cven SemoviReT <strong>da</strong>mxmare operatori G (, t β ), romelicganisazRvreba tolobiT:−βHGs(, t β ) = SΡ ⎡ () ⎤BΣ ⎣e B ts ⎦. ( 2.7)B s83


Tu gavawarmoebT (2.5) – korelaciur funqcias t-droiTi cvladismixedviT, maSin Cven miviRebT gantolebas, romelic gansazRvravs misevolucias droSi:∂ iFBA( t)= < [ H , Bs( t)]s s∂th−⋅ As> , (2.8)sa<strong>da</strong>c [...,...] – warmoadgens komutatoris agebuls ori operatorisagan.+ganvsazRvroT, agreTve evoluciis wrfivi operatorebi: W ( t,0),W( t ,0), W +( β,0), W ( β ,0)- Semdegi TanafardobebiT:i i i iHt Ht Ht Ht0 − −+0( ) ( )−βH0 βH−βH0( β,0 ) , ( β,0)h h h he = W t,0 e , e = e W t,0,, (2.9)− βH+ −e = W e e = e Wsa<strong>da</strong>c: H0 = Hs+ H Σ.Tu SemoviRebT T-namravlTa cnebas [5-6], maSin es operatorebiformalurad SesaZlebelia warmovadginoT Semdegi saxiT:W+W t( t,0)( ,0)t⎧ ⎡i⎤⎪Τ exp ⎢%a ∫dτHint( τ) ⎥ t > 0⎪ ⎣h0 ⎦= ⎨0⎪ ⎡ i ⎤⎪ Τ exp ⎢ − %∫dτHint( τ) ⎥ t < 0⎩ ⎣ ht ⎦t⎧ ⎡ i ⎤⎪Τexp ⎢− ∫dτH%int( τ) ⎥ t > 0⎪ ⎣ h0 ⎦= ⎨0⎪ ⎡i⎤⎪ Τ exp ⎢%a ∫ dτHint( τ) ⎥ t < 0,⎩ ⎣ht ⎦(2.10)sa<strong>da</strong>c:% i i0 − 0int( ) = h H τinth H τH τ e H e <strong>da</strong>:WW+β⎡⎤( β,0)=Τ exp ⎢− %a ∫ dλHint( λ) ⎥; β > 0⎣ 0 ⎦%−λH0 λH0Hint( λ)= e Hinte. (2.11)β⎡⎤β,0 =Τexp ⎢− %∫ dλHint( λ) ⎥; β > 0⎣ 0 ⎦H%( ) H e λ( )intλH0 − H0λ = eintam operatorebis sawyisi mniSvnelobebisaTvis gveqneba:( ) ( ) ( β ) ( β )W + t,0 = W t,0 = 1; W +,0 = W ,0 = 1.t= 0 t= 0 β = 0β = 0SemoRebul operatorebs gaaCniaT agreTve jgufuri Tvisebebi:W+−( t,0)= W (0. t)= W1 ( t,0);W ( t,τ ) W ( τ ,0) = W ( t,0)(2.12)84


+ −<strong>da</strong> W ( β,0) = W( 0, β) = W 1( β,0; ) W( βλ , ) W( λ,0 ) = W( β,0)nebismieri t,τ <strong>da</strong> β,λ ( β > 0, λ >0) mniSvnelobebisaTvis.(2.10) formulebSi T - qronologiurad mowesrigebis simboloa (operatorTamowesrigeba xdeba drois mixedviT marjveni<strong>da</strong>n marcxniv droismomentis zr<strong>da</strong>sTan erTad, rodesac t>0), xolo Τa- warmoadgensantiqronologiurad mowesrigebis simbolos drois mixedviT (operatorTamowesrigeba xdeba drois mixedviT marcxni<strong>da</strong>n marjvniv drois momentiszr<strong>da</strong>sTan erTad, rodesac t>0). analogiurad, (2.11) formulebSi T <strong>da</strong>warmoadgens qronologiurad <strong>da</strong> antiqronologiurad mowesrigebissimboloebs operatorebisaTvis λ temperaturuli cvladis mixedviT. un<strong>da</strong>+aRiniSnos, rom W ( t,0), W( t ,0), W +( β,0)Τ a, W ( β ,0)operatorebisaTvis droiTi<strong>da</strong> temperaturuli cvladebi H%( τ ) <strong>da</strong> H % ( λ)intoperatorebs aniWeben araintmarto raRac mniSvnelobebs, aramed gansazRvraven agreTve maTmowesrigebul Tanmimdevrobas T namravlebSi.Tu gamoviyenebT W( t ,0), W +( t,0)maSin G ( , )Bs<strong>da</strong> W ( β ,0)evoluciis operatorebs,t β operatori SesaZlebelia warmovadginoT Semdegi saxiT:−βH0( , β) ⎡ ( β,0 ) ( ,0) ( ) ( ,0)G ⎤Bst = SΡ Σ ⎣e W W t BSHt W t =s ⎦−βHs− β HΣ+= e SP ⎡Σ ( ,0) ( ,0) ( ) ( ,0)⎤⎣e W β W t BSHt W t ⎦=, (2.13)s− β Hs+( β) ( β) ⎡ ( β,0 ) ( ,0) ( ) ( ,0)= ZΣe ΡΣ⎣W W t BSHt W ts−1sa<strong>da</strong>c: ( ) ( )P β ... = Z β S Ρ ⎡ −e βH Σ... ⎤Σ ΣΣ ⎣ ⎦⎤⎦- warmoadgens bozonuri velis mdgomareobebismixedviT gasaSualoebis operators (proeqciul operators);( β )ZΣ - bozonuri velis statjamia <strong>da</strong> B () t operatori ganisazRvrebaSemdegi formuliT:sH sHt s Ht sB () t = e h Be − h . (2.14)sHscxadia, rom adgili aqvs Tanafardobas:B () t = B () t , sa<strong>da</strong>csH0 sH sisii i() Ht 0 Ht 0BsHt = e h Be −0 sh .SemoviRoT axla specialuri operacia, romelic aRiniSneba simboloTiΤ (ix. mag. [5-6,109]).LRs , ,Fs() tLRs , ,Fs() tΤ operacia garkveuli wesiT awesrigebs operatorTanamravls, romelic Sedgeba erTi Fs()t - operatorisagan <strong>da</strong> mis85


gverdiT mdgomi Aj( tj, s ) <strong>da</strong> A ( β , s)operatorebisagan. tt 1, 2,.... t nwarmoadgenenkk(0,t)-droiTi intervalis sxva<strong>da</strong>sxva wertilebs. ( j = 1,2,... n), <strong>da</strong> ββ 1, 2,... βmarian(0, β ) – temperaturuli intervalis sxva<strong>da</strong>sxva wertilebi ( k = 1,2,... m).vTqvaT simbolo aRniSnavs erTi Fs()t operatoris namravls sxvaA ( t, s ) ( j = 1,2,... n) <strong>da</strong> A ( β , s)( k = 1,2,... m) operatorebze, romlebicjjkaRniSnuli (moniSnuli) arian indeqsebiT: L (left) <strong>da</strong> R (right).kaRniSnuli operatorebis Tanmimdevruli ganlageba -Si nebismieria.operaciaLRs , ,Fs() ttj( ot , )∈ ; j 1,2,..., n∈ ; β ( β)k∈ o, ; k ∈ 1,2,... m.LΤ ganisazRvreba Semdegnairad: yvela A ( , sj j )β –operatoris movaTavsebT Fs()t – operatoris marcxniv <strong>da</strong> ganvalagebT anti-Lqronologiurad droiTi momentebis mixedviT; yvela Ak ( βk,s)operatorsLmovaTavsebT ( ,j j )A t s operatorTa marcxniv <strong>da</strong> ganvalagebT qronologiuriwesis mixedviT <strong>da</strong> bolos yvela R'( , j j' )A t s - ( j ' = 1,2,... ) operators movaTavsebTmarjvniv Fs()t operatori<strong>da</strong>n <strong>da</strong> ganvalagebT qronologiurad droiTimomentebis mixedviT. am proceduris Sesrulebis Semdeg CamovacilebT L <strong>da</strong>R indeqsebs.T Fsamrigad, am gansazRvris Tanaxmad Cven gveqneba= ⎡⎡ ⎤ ⎡ ⎤L ⎤( ⎥ ×L⎢⎢ ⎥ × ⎢ ∏RT ∏ Ak( β k , s)Ta∏ Aj( t j , s)Fs( t)T Aj′′( t j′, s)⎥ (2.15)⎣ k ⎦ ⎣ j ⎦ ⎣ j′⎦L,R,st)cxadia, romΤ operaciis niSnis qveS, Semavali yvela operatoriLRs , ,Fs() tSegviZlia ga<strong>da</strong>vanacvloT nebismierad ise, rom ar SevcvaloT Sedegi –TiTqos es operatorebi warmoadgendnen C sidideebs – vinai<strong>da</strong>n TviT esoperacia avtomaturad amyarebs wesrigs sabolood operatorTa ganlagebaSi.Cvens mier SemoRebuli operacia bunebrivad SegviZlia agreTveganvazogadod operatorebisagan Sedgenil transcendentulfunqcionalebzec. un<strong>da</strong> aRiniSnos, rom Cvens mier SemoRebuli specialurioperaciaT FsF(warmoadgens adre SemoRebuli Τs ( L ) s ( R )operaciis bunebrivL,R,st)ganzogadoebas droiT <strong>da</strong> temperaturul intervalebze [5-6,109,111-113].86


sa<strong>da</strong>c:axla ganvixiloT (2.13) formula <strong>da</strong> CavweroT is Semdegi saxiT:( ) ( )G t, = Z e G%t, : t > 0Bs−βHs( β) ( β) ( β)+G t, β =Ρ β ⎡ ( ,0) (,0) () (,0) ⎤=BsΣ ⎣W β W t B tWtsHs⎦βt⎧⎪⎡ ⎤ ⎡ ⎤=Σ ( ) ⎨Τexp − % iP β ⎢ ∫dλHint( λ) ⎥⋅Τ exp %a ⎢ ∫dτHint() τ ⎥⋅ BsH() t ×s⎪⎩⎣ 0 ⎦ ⎣h0 ⎦t⎧β⎡ i ⎤⎪⎫ , , ⎪ ⎡ ⎡ ⎤×Τexp − % LRSint() ⎬=Τ () ⎨ΡΣ( ) ⎢ΤΣexp − % L⎢ ∫dτH τ ⎥ Bt β ⎢ int( ) ⎥×sHs⎣ h0 ⎦⎪⎭⎪⎩⎢∫dλHλ⎣ ⎣ 0 ⎦×ΤaΣtt⎡i⎤⎫exp % L⎤ ⎡ i ⎤ ⎪int( ) ⋅ () ΤΣexp − % R⎢ ∫dτH τ ⎥ BsHt ⎢ ∫dτHint( τ) ⎥⎥⎬; t>0s⎣h0 ⎦ ⎣ h0 ⎦ ⎥ ⎦⎭⎪ΣBs(2.16)(2.16) formulaSi H%( λ)<strong>da</strong> H % ( τ )intoperatorebi gansazRvrulia (2.10-int2.11) tolobebiT: Τ Σ<strong>da</strong> ΤaΣsimboloebi awesrigeben mxolod im operatorebs,romlebic moqmedeben bozonur (fononur) velis cvladebze. TuLgaviTvaliswinebT (2.10-2.11) tolobebs H% int( λ)<strong>da</strong>gveqneba:∑H%( λ) = ⎡C% (, s λ) b ( λ) + C%(, s λ) b ( λ)⎤⎦L L + L+int ⎣ kH0 kH0 kH0 kH0k∑H%() τ = ⎡C% ( s, τ) b ( τ) + C%( s, τ) b ( τ)⎤⎦LR , LR , + LR ,+int ⎣ kH0 kH 0 kH 0 kH 0kH% operatorebisaTvisLR ,int( τ )(2.17)sa<strong>da</strong>c:b e be e bλH0 −λH0−λhω( k )kH( λ) = ;0k=kb e be e b+ λH0 + −λH0λhω( k ) +kH( λ) = ;0k=ki iH0τH0τ−iω( k)τ() τ =h h= ;kH0k kb e be e biiH0τ− H0τ+ h + h iω( k)τ +kH() τ = .0k=kb e be e b(2.18)i i i iH0τ − H0τ Hsτ − Hsτh h h hkH( , τ) = ( , ) () ()0kHτ =sk=kC% s C%s e C se e C sei i i iH0τ − H0τ Hsτ − Hsτ+ + h + h h + hkH( , τ) = ( , ) () () .0kHτ =sk=kC% s C%s e C se e C segamosaxuleba, romelic mocemulia (2.16) formuliT P ( β )gasaSualoebis simbolos qveS G ( t,β )% operatorisaTvis, gamoiTvlebaBs<strong>da</strong>narTSi miRebul formulis <strong>da</strong>xmarebiT (ix. <strong>da</strong>narTi, (1.4) formula). amyvelafris gaTvaliswinebiT gveqneba:Σ87


sa<strong>da</strong>c ( t β )LRS , ,,{ , ,⎤}LRs , ,( ) = ⎡Φ( )G%Bt, β T () ()exp ⎣ , ⎦ , t>0,s BHt Bs s sHtsLRSt β (2.19)Φ funqcionali ganisazRvreba Semdegi gamosaxulebiT:t τ1iω()( k τ−ξ), , ( , )2 ∫ ∫ ∑⎡⎣( 1 ( ))% LLRSt β dτ dξ Nk β e CkH(,) sξ0h0 0 kΦ =− + ×t+ − ()( − ) + + 1× % L iωk τ ξ(,) + ( ) % L(, )%LC (,) ⎤kHsτ N0 kβ e CkH sξ C − ×0 kHsτ 0 ⎦ 2 ∫dτh0τ−iω()( k τ− ξ)+× ∫ ∑⎡⎣( 1 + ( ))% R(,)%Rdξ Nk β e CkH sτ C (, ) + ( ) ×0 kHsξ N0kβ0 k× eiω()( k τ−ξ)t% + R1CkH(,)%Rsτ C (,) ⎤+ ( 1 + ( ))×0 kHsξ 0 ⎦ 2 ∫dτ∫dξ∑⎡ h ⎣ Nkβτ0 0k× e C% ( s, τ) C% (, s ξ) + N ( β) e C%( s, τ)×−iω( k)( τ− ξ) L + R iω( k)( τ− ξ)+ LkH0 kH0 k kH0t βR iω( k)( iτ−Dλ)L⎤kH⎡( )0 ⎦ ∫ ∫ ∑ ⎣ k kH0h0 0 k× C% (, s ξ) − dτ dλ 1 + N ( β) e C%(, s λ)×t+ − ( )( − ) +× % L ω k iτ Dλ( , ) + ( ) % L(, ) % L iC ( , ) ⎤kHsτ N + ×0 kβ e CkH s λ C0 kHsτ 0 ⎦ h ∫ dτβω( k)( iτ− Dλ)+× d ⎡ 1+N ( ) % L⎣(, ) % Rkβ e CkH s λ C ( , ) + ( ) ×0ksτ Nkβ∫0λ ( )β γ−ω( k)( iτ− Dλ)% + L % R⎤kH0 kH0⎦ ∫ ∫ ∑ ⎡⎣ k0 0 k−hω( k)( γ− λ) L + L hω( k)( γ− λ)+ LkH0 kH0 k kH 0LkH00( )× e C (, s λ) C ( s, τ) + dγ dλ 1 + N ( β)×× e C% (, s γ) C% (, s λ) + N ( β) e C%(, s γ)×× C%∑k(, s λ ) ⎤⎦; t > 0.+aq:k( β) ( β)( k k)h ( k )−1Σ⎡ 1⎤N = P bb =⎣e β ω −⎦(2.20)warmoadgens bozonebis (fononebis)Sevsebis ricxvebis saSualo mniSvnelobas k mdgomareobaSi; (2.18)formulebis msgavsad C% (, )kHs λ <strong>da</strong> C % +(, )0 kHs λ – operatorebisaTvis gvaqvs0Semdegi gamosaxulebebi:C% s C% s e C se e C se ;( , ) (, )λH0 () −λH0λHs()−λHskHλ =0 kHλ =sk=kC% s C% s e C se e C se .+ ( , ) + (, ) λH0 + () −λH0λHs+()−λHskHλ =0 kHλ =sk=kTu gavawarmoebT (2.19) gamosaxulebas t droiTi cvladis mixedviT <strong>da</strong>gamoviyenebT (2.16) formulas, maSin martivad vipoviT G%(, t β)operatorisaTvis evoluciur gantolebas (moZraobis gantolebas):B s88


<strong>da</strong>{ ⎡ ⎤ ⎡ β ⎤}∂i LRS , ,G%B(, t β) = T(), ()exp, ,(, )s BH s s tHs BsH t ΦsLRSt +∂th ⎣ ⎦ ⎣ ⎦LRS , , ⎧ ∂⎫+ TBH ()(), ,(, )exp, ,(, ) ; 0s s t ⎨BsH t ΦsLRSt β ⋅ ⎡LRSt tt⎣Φ β ⎤⎦⎬>⎩ ∂⎭∂iG%+B(, t β) = Ρ ( β) ⎡W( β,0 ) W ( t,0 ) ⎡H , () ( ,0)sΣsBsHt ⎤W t ⎤+s∂th ⎣⎣ ⎦ ⎦i++ ΡΣ( β) ⎡W( β,0 ) W ( t,0 ) ⎡H%int()t , BsH () ( ,0); 0hst ⎤ W t ⎤⎣⎣⎦ ⎦t >(2.21)xolo TviT Φ, ,(, t β ) funqcionalis warmoebulisaTvis miviRebTLRSSemdeg gamosaxulebas:∂1Φ (, t β) = dξ 1 + N ( β) e C ( s, ξ)×∂ttiω( k )( t−ξ), , {( ) ⎡2 ∫ ∑% LLRS k ⎣ kH0h0 k+ + − ( )( − ) +× % R(,) − % L(, ) % L iωk t ξ(,) ⎤+ ( ) ⎡ % LCkH st C ( , ) ×0 kHs ξ C0 kHst0 ⎦ Nk β e ⎣CkHs ξ0t1} 2 ∑{( )× C% (,) st − C% (, s ξ) C%(,) st ⎤ + dξ 1 + N ( β)×× eR + L LkH0 kH0 kH0⎦kh0 k−iω( k )( t−ξ){( )% L + +⎡ (,) % R(, ) − % R(,) % R⎣C ( , ) ⎤kHstC + ( ) ×0 kHs ξ C0 kHstC0 kHs ξ0 ⎦ Nkββiω( k )( t− ξ ) + +× ⎡ % L(,) % R( , ) − % R⎣(,) % R ie C ( , ) ⎤kHstC + ×0 kHs ξ C0 kHstC0 kHs ξ0 ⎦ h∫dλ∑ω( k)( it− hλ)+ +× 1 + ( ) ⎡ % L(, ) % R⎣(,) − % L( , ) % LN (,) ⎤kβ e CkH s λ C0 kHst C0 kHs λ C0 kHst0 ⎦+k− ( k)( it− h ) + ++ ( ) ⎡ % L(, )% R(,) − % L⎣(, ) % LN (,) ⎤ke ω λβ CkH s λ C ; > 00 kHst C0 kHsλC0 kHst0 ⎦t∫}0}(2.22)Tu visargeblebT (2.16, 2.22) formulebiT, <strong>da</strong> agreTve W( t ,0), W +( t,0)W ( β ,0)evoluciis wrfivi operatorebis (2.9) gansazRvrebiT <strong>da</strong> (2.12)jgufuri TvisebebiT, maSin ( , )G t β operatorisaTvis evoluciurigantoleba SesaZlebelia warmovadginoT Semdegi saxiT [109]:B s,89


ii t∂i ⎧Ht− β H⎫ 1G (, t β ) = SP [ , ]2{( 1 ( )Σ ⎨e ehH B eh⎬ − + ) ×∂∫ dξ∑N βBss s kth ⎩ ⎭ h0 kiiiω ( k ) ξ⎡− βH Ht+− Ht ⎤hhiω ( k ) ξ× e SPΣ⎢e e Ck ( s,− ξ ) Ck ( s) e Bs( t) ⎥+ Nk ( β)e ×⎣⎦iit⎡Ht− Ht ⎫− β H +⎤⎪ 1hh× SPΣ⎢e e Ck ( s, −ξ ) Ck( s) e Bs( t) ⎥⎬−2 {( 1 + ( ))×⎣⎦⎭⎪∫ dξ∑Nkβh0 k−iω ( k)ξ⎡−βH× e SPΣ⎢e Bs( t)e⎣iHth⎤C s C s e ⎥ N e⎦i+− Hthiω( k ) ξk ( ) k ( , − ξ ) +k ( β ) × (2.23)iit⎡Ht− Ht ⎫− β H1h +h⎤⎪× SPΣ⎢e Bs ( t) e Ck ( s) Ck ( s, − ξ ) e ⎥⎬+2 {( 1 + ( ))×⎣⎦⎭⎪∫ dξ∑Nkβh0 kii−iω ( k) ξ⎡− β HHt+− Ht ⎤hhiω( k)ξ× e SPΣ⎢e Ck ( s, t) Bs ( t) e Ck ( s,− ξ) e ⎥ + Nk ( β ) e ×⎣⎦⎡− β H +× SPΣ⎢e Ck ( s,t) Bs( t)e⎣iHthit− Ht ⎫ 1h⎤⎪Ck ( s, − ξ) e ⎥⎬+2 {( 1 + ( ))×⎦⎭⎪∫ dξ∑Nkβh0 kiii ( k) ⎡− H− Ht− Ht+⎤hh−i ( k)⋅e ω ξ SPΣ⎢e β e Ck ( s1− ξ) e Bs( t) Ck ( st , ) ⎥ + Nk ( β)eω ξ×⎣⎦iiβ⎡ − Ht− Ht⎫− β H +⎤⎪ 1× SP ( , − ) ( ) ( , ) − {( 1 + ( )Σ ⎢e ehC s ξ ehB t C st ⎥⎬) ×k s k⎣⎦⎪∫dλ∑N βk⎭ h0 k( , λ) ( , ) ( ) ⎤ ( β)− ω( k)( it+ hλ) + − βH ω( k)( it+hλ)× e SPΣ⎡⎣Ck s − e Ck stBs t⎦+ Nke ×β− βH + i− ω( k)( it+hλ)× SP ⎡Σ ⎣C ( , − ) ( , ) ( ) ⎤ks λ e Ck stBs t ⎦} + ∫dλ∑{( 1 + Nk( β)) e ×h0 kβ Hω( k)( it+hλ)( , λ ) ( ) ( , t) ⎦ Nk( β) e SPΣ⎡⎣ Ck( s,λ)( ) ( , ) ⎤k }; 0+ −× SP ⎡Σ ⎣Ck s − e Bs t Cks ⎤+ − ×− β H+× e Bst C st t >⎦++(2.23) gantolebaSi Semavali: C ( s,±ξ ) , C ( s,± ξ ) , C ( s,−λ ) <strong>da</strong> C ( s,−λ)operatorebi ganisazRvrebian Semdegi tolobebiT:± i Hξ ± i Hξ ±i Hξ mi Hξh h h hk k k k( ξ) ( ξ)( λ) ( λ)+ +C s, ± = e C () se ; C s, ± = e C () se− λH λH + − λH + λHC s, − = e C () se ; C s, − = e C () se .k k k kamrigad, rogorc vxe<strong>da</strong>vT G ( , )B skkkk(2.24)t β operatorisTvis (2.23) evoluciurgantolebaSi bozonuri amplitudebi ar gvaqvs. bozonuri amplitudebisgamoricxva moxerx<strong>da</strong>gasaSualoebis ( β )TL,R,SB H t)ss(specialuri operaciisa <strong>da</strong> bozonuri veliTΡ operatoris gamoyenebis Sedegad (naTelia, romΣbozonuri cvladebi (amplitudebi) gveqnebai Hte ± hevoluciis operatorebSi90


<strong>da</strong>B se −βH( , )gibsis faqtorSi). Semdeg paragrafSi (2.23) evoluciuri gantolebaG t β operatorisaTvis gamoyenebuli iqneba zusti, ganzogadoebulikvanturi evoluciuri (kinetikuri) gantolebebis misaRebad F ( t )korelaciuri funqciisTvis <strong>da</strong> grinis funqciebisTvis [110].BA s s2.2. zusti ganzogadoebuli kvanturi kinetikuri gantolebebi wonasworulikorelaciuri funqciebisa <strong>da</strong> grinis funqciebisTvisgamoviyvanoT axla zusti ganzogadoebuli kvanturi kinetikurigantolebebi korelaciuri funqciebisTvis. amisTvis ganvixiloT (2.6)formula F () t korelaciuri funqciisTvis <strong>da</strong> (2.5)-is <strong>da</strong>xmarebiT CavweroTBA s sis Semdegi saxiT:FBsAs= Zsa<strong>da</strong>c: G ( t,β )A sgamosaxuleba:( t)=−1( β ) SPB ( t)Ass[ B G ( −t,β)]ssAs=B A ( −t)ss= Z−1( β)SPs[ A G ( t,β)]sBs=(2.25)− operatorisTvis gansazRvris Tanaxmad gvaqvs Semdegi( − , ) = ( − )⎡− HG t SP A t e βAsΣ sβ⎣⎤ ⎦. (2.26)Tu gavawarmoebT (2.25) Tanafardobas t-droiTi cvladis mixedviT,maSin miviRebT:∂F∂t= ZBsAs∂( t)=∂tB A ( −t)1 ⎡ ∂( β ) SPs⎢BsG⎣ ∂t−ssAs= Z⎤( −t,β ) ⎥⎦−1⎡ ∂( β ) SPs⎢AsG⎣ ∂tTu CavsvamT (2.27) gantolebaSi G ( t,β )(2.23) formuli<strong>da</strong>n <strong>da</strong> visargeblebT ( )∂∂tB sBs⎤( t,β )⎥=⎦(2.27)operatoris gamosaxulebasSPs, Σ... operaciis qveS operatorTacikliuri ga<strong>da</strong>nacvlebis SesaZleblobiT, maSin martivi gamoTvlebis SemdegvipoviT saZiebel zust, ganzogadoebul kvantur kinetikur gantolebasBAss( t)− korelaciuri funqciisTvis [110-111,113]:91


∂∂tti1BA − t = HB ⋅A −t − d + N ⋅( ) [ ] ( ) ( 12( )− ∑ ∫ ξ ⎡⎣β )s s s s s khh k 0( , ξ) ⎡ ( ),⎤ ( ) ( β)iω( k) ξ + −iω( k)ξ⋅e Ck s − ⋅⎣Ck s Bs⎦⋅A − + ⋅−st Nke1C s − ⋅ C s B ⋅ A − t + d + N ⋅t+k ⎣ k s⎦−s⎦ 2 ∑h∫ ⎣ kk 0( , ξ) ⎡ ( ), ⎤ ( ) ⎤ ξ ⎡( 1 ( β))( ),⎤ ( ξ) ( ) ( β)⋅e ⋅ ⎡C s B ⋅C s − ⋅ A − t + N e ⋅− iω( k) ξ +iω( k)ξ⎣ k s⎦k 1s k−( ), ( , ξ ) ( t) ⎤ dθ⎡( 1 N ( β ))+⎡⎣C s B ⎤⎦⋅C s − ⋅ A −k s−k s( θ ) ⎡ ( ) ⎤ ( )− θω( k) iω( k)t+⋅ − − ⋅⎣ ⎦⋅ −k k s s−hβi− + ⋅⎦2 ∑h∫ ⎣ ke e C s, t i C s , B A t +θω( k) − iω( k)t +( β) ( θ) ⎡ ( ) ⎤ ( )+ N , , ⎤ke e Ck s −t −i ⋅⎣Ck s Bs⎦ ⋅A − ; > 0.−st t⎦k0(2.28)analogiurad SesaZlebelia miviRoT zusti, ganzogadoebuli kvanturikinetikuri gantoleba ( ) ( ) ( )AB s ss s s sF − t = AB t = A − t B korelaciuri funqciisTvis.am gantolebis gamoyvana principulad ar gansxvavdebazemoTmoyvanili gamoTvlebisagan <strong>da</strong> amitom moviyvanT mxolod sabolooSedegs:∂∂tti1A − t B = A −t ⋅ HB − d + N ⋅( ) ( ) [ ] ( 12( )− ∑∫ ξ ⎡⎣β )s s s s s khh k 0( ) ( , ξ) ⎡ ( ),⎤ ( β)iω( k) ξ + −iω( k)ξ⋅e As −t ⋅Ck s − ⋅ ⎣Ck s Bs⎦+ N ⋅−ke1A −t ⋅C s − ⋅ C s B + d + N ⋅∑∫( )+( ) ( , ξ) ⎡ ( ), ⎤ ⎤ ξ ⎡ 1 ( β)s k ⎣ k s⎦−⎦ 2h ⎣ kk 0( ) ⎡ ( ), ⎤ ( , ξ) ( β)− iω( k) ξ +iω( k)ξ⋅e ⋅ As −t ⋅⎣Ck s Bs⎦⋅Ck s − + Nke ⋅−+A ( ) ⎡ ( ), ⎤s−t ⋅⎣Ck s Bs⎦⋅C , −−k( s ) ⎤ iξ − dθ ⎡2 ⎣( 1+ Nk( β)) ⋅⎦ h+( ) ⎡ ( ), ⎤ ( , θ )θω( k) iω( k)t⋅e e As −t ⋅ Ck s Bs Cks − t+ i +⎣θω( k) iω( k)t+( β) ( ) ⎡ ( ) ⎤ ( θ)⎦+ N , , ⎤ke e As −t ⋅⎣Ck s Bs⎦ C − + ; > 0.−ks t i t⎦t∑ ∫ hkβ0(2.29)martivi SesamCnevia, rom (2.28) <strong>da</strong> (2.29) evoluciuri gantolebebi korelaciurifunqciebisTvis arian araCaketili <strong>da</strong> markoviseuli. t0 <strong>da</strong> t


zemoTwarmodgenili gamoyvanisagan <strong>da</strong> amitomac aq ar moiyvaneba. aRvniSnavTmxolod imas, rom am gantolebaTa miRebisas saWiroaΤ operaciisLRS , ,BsAs()t+xelaxali gansazRvra Wt (,0) <strong>da</strong> W (,0) toperatorebis (2.10) warmodgenisLRS , ,Sesabamisad. ( Τ operaciis xelaxali gansazRvra aucilebelia agreTveFAB s sBsAs()t( − t)korelaciuri funqciisTvis zusti, ganzogadoebuli kinetikuri gantolebismisaReba<strong>da</strong>c, rodesac t>0). naTelia, rom ganzogadoebuli kvanturikinetikuri gantolebebi BA () t <strong>da</strong> AtB () - korelaciuri funqciebisTvisssmiiReba (2.28) <strong>da</strong> (2.29) gantolebebi<strong>da</strong>n t droiTi cvladis formaluri cvlilebiT:t → –t. kinetikuri gantolebebi: BA () t <strong>da</strong> AtB () korelaciurifunqciebisTvis SesaZlebelia warmovadginoT agreTve aramarkoviseulisaxiT. Tu SevasrulebT (2.28) <strong>da</strong> (2.29) gantolebebSi t sididis cvlilebas: tHξ− Hξ→ –t, visargeblebT operatoruli tolobiT: As() t = e As( t−ξ) e ; ( ξ ∈[ 0, t])ssssssiih h,<strong>da</strong> SPs∑(...) operaciis qveS operatorTa cikliuri ga<strong>da</strong>nacvlebis SesaZleblobiT,maSin miviRebT Semdeg zust, ganzogadoebul kvantur kinetikurgantolebebs BA () t <strong>da</strong> AtB () korelaciuri funqciebisTvis [110]:ssss∂∂tti1BA ( t) =− [ HB ] A ( t) − ⎡2 ∑∫ dξ⎣( 1 + N ( β)) ×hhs s s s s kk 0( ) ⎡ ( , ξ) , ( ξ) ⎤ ( ξ) ( β)− iω( k) ξ +iω( k)ξ× e Ck s ⋅⎣Ck s − Bs − ⎦ A − + ×−st Nke1× C s C s − B − A t− + d + N ×t+k ⎣ k s ⎦−s 2h∑∫ ⎣ kk 0( ) ⎡ ( , ξ) , ( ξ) ⎤ ( ξ) ξ ⎡( 1 ( β))( , ξ) , ( ξ) ⎤ ( ) ( ξ) ( β)iω( k) ξ + −iω( k)ξ× e ⋅ ⎡⎣Ck s − Bs − ⎦ C − + ×− ks As t Nke( , ξ) , ( ξ ) ⎤ ( ) ( t ξ) ⎤ dθ ⎡( 1 N ( β))+× ⎡⎣− − ⋅k s ⎦−kC s B C s A( , θ) ⎡ ( ),⎤ ( ) ( β)−θω( k) − iω( k) t +θω( k)× e e Ck st−i ⋅ ⎣Ck s Bs⎦A + ×−st Nke( θ ) ⎡ ( ) ⎤ ( )e C st , i , ⎤⎣C s B ⎦ A t ;⎦iω( k)t +× − ⋅ ⋅k k s − sshβi− + + ×⎦2 ∑h∫ ⎣ kk0(2.30)93


∂∂tti1A ( t) B =− A ( t) ⋅[ HB ] − ⎡2 ( 1+ ( )− ∑∫ dξ⎣N β ) ×hhs s s s s kk 0( ξ) ( ) ⎡ ( , ξ) , ( ξ) ⎤ ( β)− iω( k) ξ +iω( k)ξ× e As t− ⋅Ck s ⎣Ck s − Bs − ⎦ + N ×−ket1× A t− ⋅C s C s − B − + d + N ×+( ξ) ( ) ⎡ ( , ξ) , ( ξ) ⎤ξ ⎡( 1 ( β))s k ⎣ k s ⎦−2h ⎣ kk 0( ξ) ⎡ ( , ξ) , ( ξ) ⎤ ( ) ( β)iω( k) ξ + −iω( k)ξ× e ⋅ As t− ⎣Ck s − Bs − ⎦ C + ×−ks Nke+( ξ) ⎡ ( , ξ) , ( ξ ) C ( ) ⎤⎡ks dθ( 1 Nk( β))× As t− ⎣Ck s − Bs−∑∫i⎤⎦ ⋅ + + ×− ⎦2 ∑h ∫ ⎣( ) ⎡ ( ), ⎤ ( , θ) ( β)−θω( k) − iω( k) t +θω( k)× e e As t ⎣Ck s Bs⎦⋅ C + + ×− kst i Nkekhβ0(2.31)( ) ⎡ ( ) ⎤ ( θ )e A t , , ⎤⎣C s B ⎦ C st i ;⎦− iω( kt )+×s⋅k s⋅ +−k(2.28) <strong>da</strong> (2.29) gantolebebisagan gansxvavebiT, (2.30) <strong>da</strong> (2.31) evoluciuri(kinetikuri) gantolebebi arian araCaketili <strong>da</strong> aramarkoviseuliformis. (2.3) gamosaxulebebi <strong>da</strong> (2.28)-(2.29) evoluciuri gantolebebi gansazRvravengantolebebs grinis funqciebisTvis. ase magaliTad, gantolebasr<strong>da</strong>gvianebuli grinis funqciisTvis: ( ) ( ) ( ),∂ rG ( t)= δ ( t)∂tG t = θ t ⎡⎣Ast Bs⎤⎦ηaqvs Semdegi saxe:∂[ As,Bs] η+ θ ( t)[ As( t),Bs] η∂t. (2.32)am<strong>da</strong>gvarad SesaZlebelia ganisazRvros agreTve evoluciurigantolebebi sxva <strong>da</strong>narCeni grinis funqciebisTvis (winmswrebisa <strong>da</strong>mizezobrivisTvis). (2.30)–(2.31) formulebis <strong>da</strong>xmarebiT evoluciurir(kinetikuri) gantoleba G ( t ) – grinis <strong>da</strong>gvianebuli funqciisTvisSesaZlebelia warmovadginoT Semdegi saxiT [110-111]:94


∂ riG ( t) = δ ( t) [ A , ] − ( ) ⎡⎣ ( ),[ , ] ⎤sBs θ t As t Bs Hs+η−∂th⎦η−iω( k)ξ( ) ( ){( 1k ( ))s( ) k ( )+∞1+ − + − ×2 ∑ ∫ dξθ ξ θ t ξ N β eh⎡⎣ A t ξ C sk−∞+ iω( k ) ξ+( ξ) ( , ξ ) ⎤ ( β) ( ξ) ( )× ⎡⎣B − C s − ⎤⎦ + ⎡⎦N e ⎣A t − C s ×s k−k s kη+∞1× ⎡⎣B ( −ξ) , C ( s, −ξ) ⎤⎦ ⎤⎦ } − ∑ ∫ dξθ ( ξ ) θ ( t − ξ ){( 1 + N ( β)) × (2.33)s k−2kη h k −∞e ⎡⎣A t ⎣Biω( k ) ξ×s−+ +( ξ ) ⎡ ( ξ ), C ( s,ξ) ⎤ C ( s) ⎤ N ( β )shβ− iω( k)ξ+× ⎡ ( − ) ⎡ ( − ), ( , − ) ⎤ ( ) ⎤ie⎣As t ξ ⎣Bs ξ Ck s ξ ⎦ C − ×−ks⎦2 ∑h ∫ dθηk 0− θω ( k) iω( k ) t+{( 1 Nk ( β ))e θ ( t){ e As( t) ⎡Bs, Ck ( s) ⎤ Ck( st , iθ)θω( , ) ⎡ , ( ) ⎤ ( ) } ( ) ( )− iω( k) t +( k )−ηe Ckst − θ Bs Ck s A + ⋅ ×−st Nkβ e θ t− iω( k ) t+{ ( ) ⎡⎣, ( )⎣Bs, Ck ( s) ⎦ A ( ) }}.−sts s k−k− − ⎦ ⎦+ ×k−k kη× + ⎣ ⎦ + −×⎣⎦( ) ( )iω( k ) t +e A t B C s ⎤⎦C s t + iθ −ηe C st , − iθ×1 k× ⎡ ⎤miRebuli (2.28–2.31) <strong>da</strong> (2.33) kvanturi evoluciuri (kinetikuri) gantolebebiwarmoadgenen zust, ganzogadoebul gantolebebs drois ormomentiani wonasworuli korelaciuri funqciebisa <strong>da</strong> grinis funqciisTvis[25,34,64]. gansxvavebiT kinetikuri gantolebebisagan, romlebic miRebulia [5-6,75-77] SromebSi, gamoyvanili evoluciuri gantolebebis <strong>da</strong>jaxebiTiintegralebi Seicaven rogorc maRali rigis korelaciur <strong>da</strong> grinisfunqciebs, aramed aseve sawyisi korelaciebis evoluciis amsaxvel wevrebs(ukanaskneli wevrebi (2.28–2.31 <strong>da</strong> 2.33) gantolebebis marjvena mxareSi). SevniSnavTagreTve, rom (2.28–2.31) gantolebebis marjvena mxareebis pirveliwevrebi aRweren korelaciuri funqciebis Tavisufal (ara<strong>da</strong>jaxebiT)dinamikas.−2.3. markoviseuli miaxloeba qvesistemis dinamikisTvis.miaxloebiTi gantolebebi korelaciuri funqciebisTvis<strong>da</strong>vuSvaT, rom (2.2) urTierTqmedebis hamiltoniani s qvesistemasa <strong>da</strong> S+bozonur Termostats Soris Seicavs mcire parametrs ( Ck( s ) <strong>da</strong> Ck( s)urTierTqmedebis operatorebi Seicaven mcire parametrs). aseT SemTxvevaSi,95


s qvesistemasa <strong>da</strong> S bozonur vels Soris susti urTierTqmedebis gamo,adgili eqneba droTa ierarqias:τree( t t )>> t0 = maxs,Σ, (2.34)sa<strong>da</strong>c:τ ree- warmoadgens s qvesistemis relaqsaciis maxasiaTebel dros,xolot ⋅ hβaris s qvesistemis <strong>da</strong>jaxebiTi (gabnevis) dro;s1tΣ⋅ω ~- ariskorelaciebis fluqtuaciebis milevis dro TermostatSi (ω% - bozonebisrxevebis maxasiaTebeli sixSirea). (2.34) utoloba saSualebas iZlevaSemovifargloT SeSfoTebis Teoriis meore miaxloebiT ( Hint- ur-TierTqmedebis hamiltonianis mixedviT) (2.28–2.31) evoluciur gantolebebSikorelaciuri funqciebisTvis. ase magaliTad, Tu SevasrulebT (2.28)evoluciur gantolebaSi Semdegi saxis miaxloebebs:+ +( , −ξ) ⇒ ( , −ξ) ; ( , −ξ) ⇒ ( , −ξ);0 0+ +( − − θ) ⇒ ( − − θ) ( − − θ) ⇒ ( − − θ)C s C s C s C sk kH k kHC s, t i C s, t i ; C s, t i C s, t i .k kH0 k kH 0(2.35)maSin miviRebT, drois ormomentiani wonasworuli korelaciuri funqciisTvis:( − )BA t _ ganzogadoebul, markoviseul kvantur kinetikurssgantolebas SeSfoTebis Teoriis meore miaxloebaSi [110-111]:∂∂tti1BA ( − t) = [ HB ] ⋅A ( −t) − ⎡2( 1 + ( ))×−hh∑∫ dξ⎣N βs s s s s kk 0( , ξ) ⎡ ( ),⎤ ( ) ( β)× e C s − ⋅ C s B A − t + N e ×iω( k) ξ + −iω( k)ξkH0⎣ k s⎦−s k1× C s − ⋅ C s B A − t + d + N ×t+kH01 ⎣ k s⎦−s⎦2h∑∫ ⎣ kk 0( ξ) ⎡ ( ), ⎤ ( ) ⎤ ξ ⎡( 1 ( β))( ), ⎤ ( , ξ) ( ) ( β)× e ⋅ ⎡C s B C s − A − t + N e ×− iω( k) ξ +iω( k)ξ⎣ k s⎦−kH0s khβ+× ⎡⎣C ( s), B ⎤⎦⋅C s,k s−kH ( ) ( ) ⎤ i−ξ A −t − ⎡( 1 + ( ))×0s⎦2 ∑h∫ dθ ⎣N βk( , θ) ⎡ ( ),⎤ ( ) ( β)× e e C s −t−i C s B ⋅ A − t + N e ×− θω( k) iω( k) t +θω( k)kH0⎣ k s⎦−s k( θ ) ⎡ ( ) ⎤ ( )− iω( k)t +× e C s, −− t i ⋅ , ⋅ − ⎤.kH0⎣C s Bk s⎦ A t− s⎦k0(2.36)analogiurad miiReba evoluciuri gantolebebi sxva korelaciurifunqciebisa <strong>da</strong> grinis funqciisTvis (ix. (2.29), (2.30–2.31) <strong>da</strong> (2.33) formulebi).rogorc cnobilia, xelsayrel <strong>da</strong> efeqtur meTods susta<strong>da</strong>rawonasworulimdgomareobebisa, relaqsaciuri procesebisa <strong>da</strong> kinetikuri movlenebisSeswavlisa – romlebic mimdinareoben mcire dinamiur qvesistemaSi,96


omelic urTierTqmedebs TermostatTan <strong>da</strong> gareSe velTan, - warmoadgenskorelaciuri funqciebisa <strong>da</strong> grinis funqciis meTodi.drois ormomentiani wonasworuli korelaciuri funqciebi <strong>da</strong> grinisfunqciebi warmoadgenen ZiriTad sidideebs kubos wrfivi gamoZaxilis(reaqciis) TeoriaSi [4,34,64,72-73]. (2.28–2.29) gantolebebi gansxvavdebianmsgavsi gantolebebisagan, romlebic gamoyvanili iyvnen SemTxveviTi fazebismiaxloebaSi [5-6,68,75-77], ukanaskneli wevrebiT gantolebebis marjvenamxareebSi, romlebic aRweren sawyisi korelaciebis evolucias <strong>da</strong>gavlenas <strong>da</strong>jaxebiT procesebze gabnevis (<strong>da</strong>jaxebiT) integralebSi (ix.agreTve (2.36) gantoleba). un<strong>da</strong> aRiniSnos agreTve is garemoeba, rom sawyisikorelaciebis evolucia droSi moicema markoviseuli formiT ((2.28–2.29),(2.30–2.31)) kinetikur gantolebebSi korelaciuri funqciebisTvis, <strong>da</strong> isiniar Seicaven maxsovrobis efeqtebs. Sfm-Si, rodesac t=0 drois sawyismomentSi mTeli ( s +Σ ) sistemis wonasworuli statistikuri operatori(gibsis kanonikuri ganawileba) aiReba faqtorizebuli saxiT:−1 −βH−1( ) ( ) ( ) Σ ( ) : ( ) ( )−1−βHΣρ ( β) = Z ( β)⋅e.ρ β = Z β ⋅e ⇒ ρ β ρ β ρ β = Z β ⋅eeq s s s− Hsa<strong>da</strong>c: Z ( ) S ⎡e β s− Σβ ⎤ <strong>da</strong> Z ( ) S e βHs= Ρs⎣ ⎦ΣΣ−βH s(2.37)β = Ρ ⎡ ⎤Σ Σ ⎣ ⎦– warmoadgenen statjamebs s-qvesistemisa <strong>da</strong> Σ bozonuri velisa, Sesabamisad; (anu ugulvebelvyofTurTierTqmedebis hamiltoniansHinte −βHgibsis faqtorSi <strong>da</strong> Z ( β ) statjamSi,magram vinarCunebTi Hte ± h +- operatorebSi, ris gamoc W( β ) W ( β ),0 = ,0 = 1 (ix.(2.9); (2.11) formulebi)); _ sawyisi korelaciebis evoluciis wevrebi (2.28)–(2.29) <strong>da</strong> (2.30)–(2.31); (2.36) gantolebebSi xdeba nulis toli <strong>da</strong>, rogorcSedegi am miaxloebaSi vRebulobT ganzogadoebul kvantur-kinetikurgantolebebs korelaciuri funqciebisTvis, romlebic miRebuli iyo [6,68,75-77] SromebSi.sawyisi korelaciebis Sesustebis principis (postulatis) Tanaxmad“xelovnurad” Seqmnili sawyisi korelaciebi, romlebic ganpirobebulia t=0drois sawyisi momentisTvis s-qvesistemis urTierTqmedebiT S TermostatTan,un<strong>da</strong> miilion drois mixedviT, rodesac t →∞, Tu isini ar miekuTvnebianSenaxvad sidideebs, <strong>da</strong> un<strong>da</strong> moxdes <strong>da</strong>jaxebiTi (namdvili) korelaciebisaRdgena, romlebic aRiwerebian maRali rigis korelaciuri funqciebiTa <strong>da</strong>97


grinis funqciebiT (2.28), (2.29), (2.30), (2.31), (2.36) – gantolebebis <strong>da</strong>jaxebiTintegralebSi.amrigad, ( ) − 1( )−eqZ e β Hρ β = β ⋅ - sawyisi wonasworuli ganawilebis “detalebi”TiTqos ar un<strong>da</strong> iyos arsebiTi [4]; magram, miuxe<strong>da</strong>vad amisa cxadia,rom principSi sawyisi korelaciebis evoluciis wevrebis arseboba ganzogadoebulkvantur kinetikur gantolebebSi korelaciuri funqciebisa <strong>da</strong>grinis funqciebisTvis gavlenas axdenen evoluciur procesze, romelicmimdinareobs s qvesistemaSi. s qvesistemis <strong>da</strong> S Termostatis (bozonurivelis) susti urTierTqmedebis SemTxvevaSic, sawyisi korelaciebisevoluciuri wevrebi korelaciuri funqciebisTvis kinetikur gantolebebSiar miilevian nulisaken didi droebis asimptotur areSi, rodesac( t ∼ τ >> t0;t → ∞)<strong>da</strong> iZlevian TavianT wvlils ga<strong>da</strong>tanis kinetikurrel(meqanikur) koeficientebSi (Zvradoba, eleqtrogamtaroba) s qvesistemisTvis(ix. III Tavi). Kkinetikuri koeficientebis [34], gamoZaxilis funqciis(impe<strong>da</strong>nsi, admitansi) [72-73] <strong>da</strong> dinamiuri amTviseblobis [4] gamoTvlisas;gar<strong>da</strong> amisa, relaqsaciuri procesebis Seswavlisas, romlebicmimdinareoben Ria modelur sistemebSi, <strong>da</strong> myari sxeulebis fizikiskvanturi disipaciuri sistemebis ganxilvisas, ganzogadoebul kvanturkinetikur gantolebebSi sawyisi korelaciebis evoluciuri wevrebisgaTvaliswinebas aqvs principuli mniSvneloba <strong>da</strong> maTi ugulvebelyofa arSeiZleba. miuxe<strong>da</strong>vad amisa un<strong>da</strong> aRiniSnos, rom kinetikuri movlenebisSeswavlisas am sistemebSi “namdvili” (<strong>da</strong>jaxebiTi) korelaciebi TamaSobendominirebul rols sawyis korelaciebTan Se<strong>da</strong>rebiT [4].axla ganvixiloT gansxvavebuli midgoma igive amocanisadmi, romeliceyrdnoba liuvilis superoperatorul formalizmsa <strong>da</strong> proeqciulioperatoris meTods [114-122].98


s2.4. ganzogadoebuli kvanturi evoluciuri gantolebebi korelaciurifunqciebisTvis Sfm-is gamoyenebis gareSe.proeqciuli operatoris meTodiganvixiloT drois ormomentiani wonasworuli korelaciuri funqcia( )A t B <strong>da</strong> warmovadginoT is Semdegi saxiT:sA ( t)BSS−1= Z ( β)SPs∑−βHiLt[ B e e A ]ss(2.38)(2.38) formulaSi Cven SemoviReT liuvilis superoperatoris (L) cneba,romelic moqmedebs nebismier D-operatorze Semdegi wesiT:1hii± −±= [ , ] : = h Hth HtiLt± iLtLD H D e D e De , anu e D = D( ± t)<strong>da</strong> =−( )t=0sD D t .liuvilis sruli L superoperatori Caiwereba Semdegi saxiT:L L L L= + + , sa<strong>da</strong>c L s= [ H ,...], L ∑= [ H ,...]<strong>da</strong> ... [ ,...]Σi1...sh1...∑h1= ; (2.1)–(2.2)hLiHint−hamiltonianis TiToeuli wevris Sesabamisad. (2.38) formuli<strong>da</strong>n gamomdinarecxadia, rom korelaciuri funqciebis dinamika xelsayrelia ganvixiloTSemdegi superoperatorebis <strong>da</strong>xmarebiT, romlebic moqmedeben D D-operatorze Semdegi wesiT:−1( ) ( β )−βH iLtR t D = Z SΡ ⎡ ⎤Σ ⎣e e ΡD⎦−1( ) ( β )−βH iLtI t D = Z SΡ ⎡ ⎤Σ ⎣ e e QD ⎦ ,(2.39)sa<strong>da</strong>c: Ρ warmoadgens Termostatis (bozonuri velis) mdgomareobebismixedviT gasaSualebis proeqciul operators:−( β) ( ρ ) ρ ( β)Ρ =Ρ; Ρ=Ρ ; Ρ D= SΡ D = D ; = Z e2 1Σ Σ Σ Σ Σ Σ(2.38) gamosaxuleba ( )−βHΣ( β) S ( e ) Q Q ( β)−βHΣZ = Ρ ; = = 1 −Ρ.Σ Σ Σss(2.40)A t B korelaciuri funqciisaTvis CavweroTSemdegi formiT:A t)( = A B ( t)= SP [ B R(t)A ]SB SSS− . (2.41)sssP <strong>da</strong> Q – proeqciuli operatorebis <strong>da</strong>xmarebiT martivad miviRebTSemdeg zust moZraobis gantolebebs R(t) <strong>da</strong> I(t) superoperatorebisaTvis:∂R( t) = iR( t) ΡLΡ+ iI( t)QLΡ;∂t∂I( t) = iI( t) QLQ+ iR( t)ΡLQ.∂t(2.42)99


Tu CavatarebT (2.42) gantolebis integrebas I(t) superoperatorisaTvis,maSin Cven miviRebT Semdeg gamosaxulebas:sa<strong>da</strong>c:t∫0( ) = ( ) ( ) + ( ) Ρ ( − )I t I 0 M t i dτR τ LQM t τ ,(2.43)Q−1( 0) ( )−βHI Z S e QQ= β Ρ Σ(2.44)aris I(t)-superoperatoris sawyisi mniSvneloba <strong>da</strong> M ( t) = exp[ iQLQt]warmoadgens “masur” superoperators.Tu CavsvamT I(t)-superoperatoris (2.43) gamosaxulebas (2.42) formulispirvel gantolebaSi, maSin Cven vipoviT zust, araerTgvarovan evoluciurgantolebas R(t)-superoperatorisaTvis:∂tR( t) = iR( t) ΡLΡ+ iI( 0) MQ( t) QLΡ− dτR( t) ΡLQMQ( t−τ)QLΡ∂t∫ . (2.45)0miRebuli gantoleba gansazRvravs evoluciur gantolebas (2.41)korelaciuri funqciisaTvis. marTlac, Tu visargeblebT (2.39) gansaz-RvrebiTa <strong>da</strong> S Ρ s ,Σoperaciis qveS operatorTa cikliuri ga<strong>da</strong>nacvlebis SesaZleblobiTa<strong>da</strong> (2.41)–(2.45) formulebiT, maSin martivad vipoviT Semdegevoluciur gantolebas korelaciuri funqciisTvis [119]:∂∂t( ) [ ] ( ) ⎡ ( )AB − = Ρ Ρ − + ⎣ Ρ ⎤s st i L As Bs t i QMQ t QL As⎦Bs−t∫0( ) ⎤ ( )− dτ ⎡⎣ΡLQMQ t−τ QLΡAs⎦Bs−τ.Q(2.46)(2.45) <strong>da</strong> (2.46) gantolebebi warmoadgenen zust, aramarkoviseul evoluciurgantolebebs R(t) superoperatorisa <strong>da</strong> AB ( t)ss− korelaciurifunqciisTvis. am gantolebaTa araerTgvarovani wevrebi (meore wevrebi (2.45),(2.46) ganatolebaTa marjvena nawilSi) aRweren sawyisi korelaciebisevolucias drois mixedviT, romlebic ganapirobebulia s qvesistemisurTierTqmedebiT S TermostatTan (bozonur velTan) drois sawyis moment-Si: t=0. amis gamo, sawyisi amocanis (koSis amocana) amoxsnisas (2.45) gantolebisaTvis(<strong>da</strong> korelaciuri funqciis povnisaTvis) saWiroa codna ara martosuperoperatorisa – R(0), aramed agreTve I(0) sididisa. Tu maxsovrobasawyisi korelaciebisa drois mixedviT miileva, maSin evoluciis procesSidominirebs <strong>da</strong>jaxebaTa gavlena. magram, miuxe<strong>da</strong>vad amisa, principSi sawyisi100


korelaciebis wevrebis arseboba evoluciur gantolebebSi, romelicganapirobebulia I(0)-is arsebobiT, gavlenas moaxdens relaqsaciur procesze,romelic aRiwereba korelaciuri funqciiT, qvesistemis susti urTierTqmedebisSemTxvevaSiac TermostatTan. mogvianebiT Cven vaCvenebT, rom sawyiskorelaciebs SeaqvT TavianTi wvlili s qvesistemis (mag. eleqtronis) ga<strong>da</strong>taniskinetikur koeficientSi (eleqtrogamtaroba) [115-122].bevrad ufro efeqturi <strong>da</strong> xelsayrelia, Tu Cven ganvixilavT evoluciiszust <strong>da</strong> erTgvarovan gantolebas, romelSiac sawyisi korelaciebimoicema aracxadi saxiT. imisaTvis, rom vipovoT aseTi saxis gantoleba,visargebloT cnobili integraluri operatoruli igiveobiT:β−βH −βH0 −βH λH−λH0λint0e = e −∫ d e e H e , (2.47)sa<strong>da</strong>c H0moicema (2.9) formuliT. am igiveobis gamoyenebiT, adviliaimis Cveneba, rom adgili aqvs Semdeg gantolebaTa sistemas I(t) <strong>da</strong> I(0)-superoperatorebisaTvis, romlebic gamomdinareoben (2.43) <strong>da</strong> qvemoTmoyvanili gantolebi<strong>da</strong>n:( 0 ) ( ) ( , β) ( ) ( , β)I =−R t I t −I t I t(2.48)Q<strong>da</strong> romelic miiReba (2.47) gamosaxulebisa <strong>da</strong> I(t)-superoperatorisTvis (2.44)sawyisi pirobi<strong>da</strong>n. (2.48) gantolebaSi Cven SemoviReT integralurisuperoperatori, romelic ganisazRvreba Semdegi tolobiT:βiLt λH λHQ ( t,β) dλe − e Hinte −Q0QI =∫ . (2.49)Tu amovxsniT (2.43) <strong>da</strong> (2.48) gantolebebs I(0)-is mimarT <strong>da</strong> CavsvamT(2.45) gantolebaSi, maSin Cven miviRebT saZiebel zust, erTgvarovan Caketilgantolebas R(t)-superoperatorisaTvis:∂−1R( t) = iR( t) ΡLΡ−iR( t) ΡI ( , ) ⎡⎣1 + ( ) I ( , ) ⎤Qt β MQ tQt β ⎦ ×∂tt( ) τ ( τ) ( τ ) ( , β) ⎡1( )∫× M t QLΡ+ d R ΡLQM t− I t ⎣ + M t ×Q Q Q Q0−1( β) ⎤ ( ) τ ( τ ) ( τ)×I t, ⎦ M t QLΡ− d R ΡLQM t− QLΡ.Q Q Q0t∫(2.50)un<strong>da</strong> aRvniSnoT, rom miRebuli gantolebebi SesaZlebelia gavamartivoT,Tu visargeblebT Semdegi TanafardobebiT:L Ρ= 0; Ρ LQ = QL Ρ= 0; ΡLΡ= 0. (2.51)Σs s i101


<strong>da</strong>bolos, Tu gamoviyenebT (2.50)–(2.51) formulebs, (2.46) gantolebisnacvlad miviRebT Semdeg zust kvantur evoluciur (kinetikur) gantolebaskorelaciuri funqciisTvis [119]:∂∂t( ) [ ] ( ) { ( , β )AB − t = i ΡL ΡA B −t −i ΡI t ×s s s s s Q−1( ) ( β) ⎤} ( )× ⎡⎣1 + MQ t IQ t,⎦ MQQLiΡAs Bs− t + dτ×{ LQM ( t τ ) ( t, β) ⎡1 M ( t) ( t,β)× Ρi Q− IQ ⎣ +QIQ⎤⎦×( ) } ( τ ) τ ⎡ ( τ)× M t QLΡA B − − d ⎣ΡLQM t− Q×Q i s s i Q0] ( τ )× LΡA B −i s s.t∫t∫0−1(2.52)(2.50)–(2.52) evoluciur gantolebebs gaaCniaT sakmarisad rTulioperatoruli struqtura. sawyisi korelaciebis evolucia droSi aRiwereba(2.49) integraluri superoperatoriT; igi Sedis evoluciur gantolebebSirogorc markoviseuli, ise aramarkoviseuli formiT (meore <strong>da</strong> mesamewevrebi (2.50) <strong>da</strong> (2.52) gantolebebis marjvena nawilSi). Sfm-is dros,− H0rodesac (2.38) korelaciuri funqciis gansazRvrebaSi Cven viRebT e β –operators, nacvladHe β-gibsis statistikuri operatorisa, vRebulobT, romI(0)=0, rogorc es naTlad Cans (2.39) <strong>da</strong> (2.40) formulebi<strong>da</strong>n (vinai<strong>da</strong>n PQ=0).am garemoebas mivyavarT im Sedegamde, rom integraluri superoperatorixdeba nulis toli ( ( t β )I , ≡ 0), rac Tavis mxriv iwvevs sawyisiQkorelaciebis evoluciis amsaxveli wevrebis gaqrobas (isini xdebian nulistoli) (2.50) <strong>da</strong> (2.52) evoluciur gantolebebSi. rogorc Sedegi <strong>da</strong> kerZoSemTxveva Cven vRebulobT evoluciur gantolebas korelaciuri funqciis-Tvis, romelic gamoyvanilia [75-77] SromebSi.evoluciuri gantolebebi (2.3)-grinis funqciebisTvis gamomdinareoben(2.52)-gantolebi<strong>da</strong>n. ase magaliTad, grinis <strong>da</strong>gvianebuli funqciisTvisgveqneba gantoleba:∂∂t∂= + − −∂t∂−ηθ( t) BAs s( t) .∂t( ) δ ( ) [ ] θ( ) ( )rG t t ABs st ABs stηnaTelia, rom evoluciuri gantoleba ( )(2.53)AB t korelaciuri funqciisTvismiiReba (2.52) gantolebi<strong>da</strong>n, Tu gamoviyenebT Casmas t → –t [119, 121-122].ss102


2.5. Termostatis bozonuri amplitudebis gamoricxva evoluciurigantolebi<strong>da</strong>n korelaciuri funqciisaTvis. markoviseuli miaxloebaqvesistemis dinamikisTvisganvixiloT axla ufro detalurad (2.52) evoluciuri gantolebakorelaciuri funqciisTvis. advili misaxvedria, rom (2.52) gantolebaSeicavs Termostatis (bozonuri velis) amplitudebs, romlebic ar ariangamoricxuli am gantolebi<strong>da</strong>n. <strong>da</strong>vuSvaT, rom hamiltoniani Hint(liuviliani L i ) Seicavs mcire parametrs (susti urTierTqmedebis SemTxvevaqvesistemasa <strong>da</strong> Termostats Soris); maSin (2.52)-gantolebi<strong>da</strong>n principSiSesaZlebelia bozonuri amplitudebis gamoricxva. am amocanisga<strong>da</strong>sawyvetad gavSaloT mwkrivebad superoperatorebi, romlebicfigurireben (2.52)-gantolebaSi ( )mixedviT. gveqneba:L H liuvilianis (hamiltonianis)iint−1k( ) ( β) ( ) ( ) ( β)⎡⎣1 + M t I t, ⎤⎦ = −1 ⎡⎣M t I t,⎤⎦Q Q Q Qk=0∞∑( n) (0)0( ) = ( );( ) =Q Q Qk = 0∞∑M t M t M t eiLtkt t1tn−1( n)iL0( t−t1) iL0( t1−t2)Q ( ) ∫ 1∫ 2... ∫ n i i...0 0 0M t = dt dt dt e iQLe iQL ×iL0( tn −1−tn)iLt 0 n× e iQLein=( ); 1,2,...t−iLt−iLt0e = e Τexp⎢−i∫Li( ξ)d0λλHλH0e = e Τ'exp⎢∫Hint( γ ) d0−( ξ) ; ( γ)⎡⎣⎤ξ⎥⎦⎤γ⎥⎦L = e Le H = e H eiiL 0 ξ iL 0 ξ −γH int0 γHiint00⎡⎣L = L + LsΣ,(2.54)sa<strong>da</strong>c T <strong>da</strong> T’ simboloebi aRniSnaven operatorTa mowesrigebas Sesabamisadξ <strong>da</strong> γ cvladebis mixedviT.s qvesistemis S TermostatTan susti urTierTqmedebis SemTxvevaSi(2.54) gaSlebi formalurad SegviZlia ganvixiloT rogorc SeSfoTebisTeoriis mwkrivebi <strong>da</strong> gamovTvaloT wevrebi (2.50)–(2.52) gantolebebismarjvena nawilebSi mocemuli sizustiT. martivi saCvenebelia, rom aseTigaSlebisas urTierTqmedebis mixedviT im SemTxvevaSi, rodesac H Σ<strong>da</strong>aqvT (2.2) saxe, nulisgan gansxvavebuli iqnebian mxolod iseTi saSualoHint103


sidideebi – ... Σ, romlebic Seicaven bozonebis <strong>da</strong>badebisa <strong>da</strong> gaqrobisoperatorebis erTnair raodenobas. amitom aseTi saxis saSualoebi toliiqneba sidideebis, romlebic proporciuli iqnebian bozonebis SevsebissaSualo ricxvebis namravlebis. amrigad, bozonuri (fononuri)operatorebi (amplitudebi) mTlianad gamoiricxeba (2.52) evoluciurigantolebi<strong>da</strong>n wonasworuli korelaciuri funqciisaTvis.<strong>da</strong>vuSvaT, rom susti urTierTqmedebis gamo, romelsac adgili aqvs sqvesistemasa <strong>da</strong> S Termostats Soris, gvaqvs droTa ierarqia mTel ( s +Σ )sistemaSi, romelic aRiwereba (2.34) utolobiT. (2.34) utolobissamarTlianoba gvrTavs nebas CavataroT markoviseuli miaxloeba (2.50)–(2.52)gantolebebSi; Tu SemovisazRvrebiT SeSfoTebis Teoriis meore miaxloebiTurTierTqmedebis ( )intiH L hamiltonianis (liuvilianis) mixedviT, visargeblebT(2.54) gaSlebiT <strong>da</strong> SevasrulebT Semdeg miaxloebebs:Q( ) ( βQ Q )(0)( ) ( )0( , ) ( , )−1⎡⎣1 + M t I t, ⎤⎦⇒1iL0tM t ⇒ M t = esQQQI t β ⇒I t β = dλe e H e QiL0( t−τ)( −τ) ⇒ ( − )B e B tβ∫0−iL0t λH0 −λH0ints.(2.55)maSin (2.52) evoluciuri gantoleba martivdeba <strong>da</strong> igi iRebs saxesmarkoviseuli, ganzogadoebuli kvanturi kinetikuri (evoluciuri)gantolebisa wonasworuli korelaciuri funqciisTvis AB ( t)∂∂tβ−iLt0 λH0( − ) = [ ] ( − ) − ⎡s s s s sλ Ρ ×AB t i LA B t i d⎣e et−λH0 iLt 0 iL0( t−τ)× H ⎤inte e LA ⎦ ( − ) −∫⎡⎣Ρ ⎤i sBs t d LeiLAi s⎦×0( )iL0( t−τ)×s−e B t.∫0ss− [119]:τ (2.56)miRebuli (2.56) gantoleba korelaciuri funqciisTvis jer kidevSeicavs gamouricxav bozonur amplitudebs. Tu visargeblebT H Σ<strong>da</strong>hamiltonianebis – (2.2) cxadi saxiT <strong>da</strong> gamovricxavT bozonur operatorebszemoT aRwerili proceduris <strong>da</strong>xmarebiT, maSin (2.56) evoluciurigantoleba korelaciuri funqciisTvis Caiwereba Semdegi saboloo saxiT[119]:H int104


∂∂t⎡⎡ti1iω( k)ξs s ( − ) =− [ s,s] ( − ) −2 { ( ) ×− s ∫ ξ∑kβhh0 kAB t A H B t d N e( )( ) ⎤ ( ξ) ⎤ ( ) ( β)+ −iω( k)ξ×⎣⎣As, Ck s ⎦ ⋅C , − − + 1+ ×−ks⎦Bs t Nke−ω( k)β+ − ( )( + )⎡ , ( ) ( , ) ⎤iiωk t ihλ×⎣⎡⎣As Ck s ⎤⎦⋅C − ( − ) + { ( ) ×− ks ξ⎦Bs t ∑( ) h ∫dλ Nkβ eω k0 k( )( , hλ) ⎡⎣, ( ) ⎤⎦( ) 1 ( β)−+( , hλ) ⎡ , ( ) ⎤ ( ) },× C s −t −i ⋅ A C s B − t + + N e+ iω( k )( t + ihλ)k s k s k× C s −t−i ⋅⎣A C s⎦B −tk s k−s×(2.57)sa<strong>da</strong>c: Nk( β )( k)e β h= ⎡ω −saSualo ricxvs, <strong>da</strong>⎣1⎤⎦−1- warmoadgens bozonebis (fononebis) Sevsebis± iLZ s+ ± iLZ s +( 1± ) = ( );( 1± ) = ( )( )[ , ] = − m β h ω kED ED e DE.C s Z e C s C s Z e C sk k k kxolo± ω( k)(2.58)nebismieri E <strong>da</strong> D operatorebisaTvis.(2.57) gantolebis gamoyvanisas, Cven visargebleT agreTve SemdegiTanafardobebiT:e b = e b ; e b = e b± iLt Σ m i ω( k ) t ± iLt Σ + ± i ω( k ) t +k k k k+ +( b , b ) N ( ) ; ( b , b ) ( 1 N ( ))+ +Ρ ( bk, bk') =Ρ ( bk, bk') = 0.Ρ = β δ Ρ = + β δk k' k kk , ' k k' k kk , '(2.59)Tu SevasrulebT t → –t Casmas (2.57) evoluciur gantolebaSi, maSinmartivad miviRebT ganzogadoebul kvantur kinetikur gantolebas AB ( t )korelaciuri funqciisTvis:∂∂ti1AB ( t) = [ A , H ] B ( t) − ⋅2{ ( ) ×− ∫ dξ∑ N βhhs s s s s k0 k⎡⎣⎣( ) ⎤ ( ) ⎤⎦ ξ ( ) ( ( β))− ⎦−ω( k)β+i( ) ⎤⎦( ξ) ⎤ ( )− ⎦ω( k)} ∫ λ− iω( k)ξ+× e ⎡As, Ck s ⋅ Ck s, Bs t + 1+ Nk×⎡iω( k)ξ× e⎣⎡⎣As, Ck s ⋅Ck s,Bst − d ×h0∑iω( k )( t − ihλ)+{ N ( β)e C ( st , ihλ) ⎡A , C ( s) ⎤ B ( t)× − ⋅ ⎣ ⎦ +kk k s k−s−iω( k )( t −ihλ)+( 1 N ( β ))e C st , ikk( hλ) ⎡A C ( s) ⎤ Bs k s( t) }+ + −t⋅ ⎣, ⎦.−s(2.60)(2.57)–(2.60) gantolebebi gansxvavdeba Sfm-Si miRebuli gantolebebisagan[75-77]. mesame wevrebis arsebobiT gantolebaTa marjvena nawilSi,romlebic aRweren sawyisi korelaciebis evolucias [114, 119,121-122].s105


<strong>da</strong>bolos, un<strong>da</strong> aRiniSnos erTi principuli sakiTxi, romelic exebasawyisi korelaciebis evoluciis wevrebis gaTvaliswinebas ganzogadoebulikvanturi kinetikuri gantolebebis <strong>da</strong>jaxebiT integralebSi,wonasworuli korelaciuri <strong>da</strong> grinis funqciebisTvis. Sfm – mTeli (s + S)-kvanturi dinamiuri sistemis statistikuri operatorisTvis – <strong>da</strong>fuZnebuliaim <strong>da</strong>Svebaze <strong>da</strong> aRwers iseT situacias, rodesac drois sawyisi t = 0momentisTvis adgili ar aqvs korelaciebs s-kvanturi dinamiuri qvesistemisa<strong>da</strong> S-Termostatis mdgomareobebs Soris, <strong>da</strong> drois am momentisTvisxdeba “CarTva” urTierTqmedebisa, rogorc qvesistemasa <strong>da</strong> TermostatsSoris, aseve qvesistemasa <strong>da</strong> gareSe velebs Soris. cxadia, rom aseTSemTxvevaSi mTliani (s + S)-kvanturi dinamiuri sistemis sawyisistatistikuri ganawileba (statistikuri operatori drois sawyis momentSi)aiReba faqtorizebuli saxiT (ix. (2.37) formula). amitom, rogorc ukve iyoaRniSnuli, rogorc Sedegi vRebulobT ganzogadoebul kinetikur gantolebebskorelaciuri <strong>da</strong> grinis funqciebisTvis, romelTa <strong>da</strong>jaxebiTiintegralebi ar Seicaven sawyisi korelaciebis evoluciis wevrebs [75-77].yvela im realur modelebSi fizikuri sistemebisa (kvanturidisipaciuri sistemebi, Ria arawonasworuli modeluri sistemebi <strong>da</strong> sxv.),romlebsac ganixilavs statistikuri fizika (meqanika) <strong>da</strong> Termodinamika,fizikuri kinetika <strong>da</strong> a.S., qvesistemis urTierTqmedebis gamo TermostatTan,s dinamiuri qvesistemac <strong>da</strong> S Termostatic erTad Seadgenen ganuyofelnawilebs erTiani mTliani dinamiuri sistemisa - (s + S) (qvesistema plusTermostati). ufro metic, SeiZleba iTqvas, rom qvesistemasa <strong>da</strong> TermostatsSoris urTierTqmedebis gamo, eqsperimentebze faqtiurad SeuZlebelia maTierTmaneTisagan gancalkeveba. aseT situaciaSi, kinetikuri movlenebis srul<strong>da</strong> adekvatur aRwerasa <strong>da</strong> gamokvlevas, romlebic mimdinareoben mcirekvantur dinamiur qvesistemaSi, Seesabameba – mTeli (s + S) dinamiurisistemis statistikuri operatoris sawyisi mniSvneloba – ara Sfm-is tipis,aramed iseTi saxis sawyisi mniSvnelobebi mTeli sistemis statistikurioperatorisa, romlebic iTvaliswineben korelaciebs kvanturi dinamiuriqvesistemisa <strong>da</strong> Termostatis mdgomareobebs Soris drois sawyisi momentisaTvis(t = 0) (arafaqtorizebuli sawyisi statistikuri ganawilebebimTeli (s + S)-sistemisa) [19,21].106


Cvens mier <strong>da</strong>smuli amocanis Tanaxmad, mTeli (s + S) dinamiurisistema drois sawyisi t = 0 momentisaTvis imyofeba statistikuri wonasworobismdgomareobaSi, romelic aRiwereba gibsis kvanturi kanonikuri (andidi kanonikuri) ganawilebiT mTeli (s + S) sistemisTvis:ρeq β Z β e β H−1−( ) = ( ) ,<strong>da</strong> drois amave t = 0 momentSi xdeba urTierTqmedebis “CarTva” mTel (s + S)sistemasa <strong>da</strong> gareSe wyaroebs (velebs) Soris. amis gamo, kinetikuriprocesebis mkacrad, zustad <strong>da</strong> koreqtulad aRsawerad <strong>da</strong> Sesaswavlad,romlebic mimdinareoben mcire kvantur dinamiur qvesistemaSi, romelicurTierTqmedebs TermostatTan (mag. bozonur (fononur) velTan), sawyisikorelaciebisa <strong>da</strong> sawyisi korelaciebis evoluciis wevrebisgaTvaliswinebas - ganzogadoebuli kvanturi kinetikuri gantolebebis<strong>da</strong>jaxebiT integralebSi, wonasworuli korelaciuri <strong>da</strong> grinisfunqciebisTvis s-qvesistemis dinamiuri sidideebisaTvis– aqvs principulimniSvneloba, <strong>da</strong> maTi apriori ugulvebelyofa (ignorireba) <strong>da</strong>uSvebelia [19,21, 110, 114-115, 119-122].miRebuli ganzogadoebuli kvanturi kinetikuri gantolebebi droisormomentiani wonasworuli korelaciuri funqciebisTvis, sadisertacionaSromis III TavSi gamoyenebuli iqneba eleqtronuli <strong>da</strong> polaronuliga<strong>da</strong>tanis movlenebis gamosakvlevad myar sxeulebSi – naxevargamtarebsa <strong>da</strong>ionur kristalebSi [114-118, 120-122,125].107


Tavi III. naxevargamtarebsa <strong>da</strong> ionuri kristalebSi eleqtronuli <strong>da</strong>polaronuli gamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturuli Zvradobis kvanturiTeoria <strong>da</strong>fuZnebuli kubos wrfivi gamoZaxilis Teoriazerogorc ukve aRniSnuli iyo Sesavalsa <strong>da</strong> literaturis mimoxilvaSi,myar sxeulebSi ga<strong>da</strong>tanis wrfivi movlenebis Sesaswavlad <strong>da</strong> denismatareblebis ga<strong>da</strong>tanis kinetikuri (meqanikuri) koeficientebis gamosaTvlelad,SesaZlebelia gamoyenebuli iqnas ori gansxvavebuli midgoma: 1)<strong>da</strong>fuZnebuli kubos wrfivi gamoZaxilis (reaqciis) Teoriaze, <strong>da</strong> 2)<strong>da</strong>myarebuli kinetikur gantolebaze denis ga<strong>da</strong>mtanebis ganawilebisfunqciisTvis, romelic cnobilia rogorc bolcmanis gantoleba.rogorc ukve araerTxel iyo xazgasmuli, eleqtronuli <strong>da</strong> polaronuliga<strong>da</strong>tanis movlenebis Teoriis Seswavla myar sxeulebSi <strong>da</strong> maTikinetikuri maxasiaTeblebis gamoTvla, warmoadgens erT-erT aqtualuramocanas eleqtronisa <strong>da</strong> didi radiusis mqone polaronis kinetikisTanamedrove TeoriaSi [29-30,37-38]. gamoviyenoT axla wina TavSi gamoyvaniliganzogadoebuli kvanturi kinetikuri gantolebebi eleqtronuli <strong>da</strong>polaronuli ga<strong>da</strong>tanis movlenebis Sesaswavlad naxevargamtarebsa <strong>da</strong>ionur kristalebSi; kerZod – ganvixiloT konkretuli magaliTebi kvanturidinamiuri qvesistemebisa, romlebic urTierTqmedeben fononur velTan:eleqtron-fononuri sistema (eleqtronis urTierTqmedeba (gabneva)polarul optikur <strong>da</strong> akustikur fononebTan), polaronis latinjer-lus(fg) modeli <strong>da</strong> maTze <strong>da</strong>yrdnobiT avagoT denis ga<strong>da</strong>mtanebisTviseleqtrogamtarobisa <strong>da</strong> Zvradobis wrfivi kvanturi Teoria <strong>da</strong> gamov-TvaloT kinetikuri maxasiaTeblebi (korelaciuri funqciebis milevis devrementebi,relaqsaciis droebi (sixSireebi) <strong>da</strong> sxv.) <strong>da</strong> ga<strong>da</strong>tanis meqanikurikoeficientebi (kuTri eleqtrogamtaroba, <strong>da</strong>baltemperaturuli Zvradoba,<strong>da</strong> sxv.) kvanturi disipaciuri (qve) sistemebis am kerZo modelebisTvis. ganixilebamidgoma, romelic eyrdnoba kubos wrfivi reaqciisa <strong>da</strong> SeSfoTebisTeorias.108


3.1. eleqtron-fononuri sistema. eleqtronis <strong>da</strong>balsixSirulieleqtrogamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturuli Zvradobis gamoTvla sustieleqtron-fononuri urTierTqmedebis SemTxvevaSiganvixiloT SemTxveva nawilakis (eleqtronis) urTierTqmedebisa<strong>da</strong>kvantul fononur velTan (eleqtron-fononuri sistema), rodesac mTelisistemis hamiltoniani moicema (1.13) formuliT <strong>da</strong> eleqtronis energiasgamtarobis zoni<strong>da</strong>n aqvs Semdegi zogadi saxe: Hs=ΤΡ ( ).rogorc cnobilia, kubos wrfivi reaqciis Teoriis Tanaxmadsistemaze moqmedi susti intensivobisa <strong>da</strong> ω-sixSiris mqone gareSe eleqtrulivelis SemTxvevaSi, eleqtrogamtarobis tenzori SesaZlebeliagamovsaxoT “deni-denze” korelaciuri funqciis saSualebiT. kubosformulis Tanaxmad eleqtrogamtarobis tenzori Caiwereba Semdegi saxiT[4,25,64,72,83]:⎛ 1 ⎞+∞ ⎜thβ hΩi⎟21σ ( ω ) =− Ω⎝ ⎠∫ dI{ µν , }( Ω)µνπhΩ Ω−ω −iε−∞+ε > 0; ε → 0 ( µν , = xyz , , ),+∞{2∫−∞ν µµ ν1 iΩtsa<strong>da</strong>c: I µ , ν}(Ω)= dte [ j (0) J ( t)+ j ( t)J (0) ](3.1) formulis Tanaxmad eleqtrogamtarobis tenzoris disipaciurinawilisTvis gveqneba:.(3.1)12 th( βhω)Re σ ( ω) dtcos( ωt) (), t∞s 2sµν≡Ψµνhω∫0(3.2)sssa<strong>da</strong>c: σ ( ω ) <strong>da</strong> Ψ () t warmoadgenen gamtarobis σ ( ω ) tenzorisa <strong>da</strong>µνµνΨ () t korelaciuri funqciis simetriul nawilebs:µνs 1σµν( ω) = ⎡ ( ) ( ) ;2⎣σµν ω + σνµω ⎤⎦s 1 1Ψµν() t = ⎡ () t () t () t ( t) ;2⎣Ψ µν+Ψνµ⎤⎦ = ⎡2⎣Ψ µν+Ψµν− ⎤⎦(3.3)1 1Ψµν() t = ⎡ jν (0) jµ () t + jµ () t jν(0) ⎤= ⎡ jν (0) jµ () t + jµ (0) jν( −t)⎤2⎣ ⎦ 2⎣ ⎦µ µiLt<strong>da</strong> j () t = e j (0) aris r j -eleqtruli denis operatoris µ komponenti haizenbergiswarmodgenaSi. amrigad, eleqtrogamtarobis gamosaTvleladµν109


2esaWiroa vipovoT: Ψ () = (0) ()2 ⎡µνt⎣Vν Vµ t + + V (0) ( − ) ⎤µVν t⎦korelaciuri funqciismniSvneloba. V rwarmoadgens eleqtronis siCqaris operators gamtarobiszonaSi. imisaTvis, rom vipovoT Ψ () t korelaciuri funqciis sidide,µνgamoviyenoT naSromis II-TavSi miRebuli (2.57) <strong>da</strong> (2.60) miaxloebiTi evoluciurigantolebebi wonasworuli korelaciuri funqciebisTvis eleqtronfononurisistemisTvis, <strong>da</strong> visargebloT mTeli sistemis hamiltonianis(1.13) gamosaxulebiT. miaxloebiT evoluciur (kinetikur) gantolebaseleqtronis drois ormomentiani wonasworuli korelaciuri funqciisTvis“siCqare-siCqare” eqneba Semdegi saxe ( H A V B Vs s ν s µ )∂∂t−( k ) ν µ }−=ΤΡ ( ); = ; = .[120-122]:i1= ⎡ ΤΡ⎤ − +t2−iω( k ) ξV (0) () , ( ) () ⎡νVµ t ⎣Vν ⎦ V ( )− µt2 ∫ dξ∑V⎣e Nkβkhh0 krriω( k ) ξ ikr −ikr( ξ ) iω( k ) ξ −iω( k)ξ( 1 ( ))⎤ ⎡ , ⎤ () ⎡kβ⎦ ⎣ ν ⎦ µ( )−⎣kβ+ e + N V e e V t − e N + e ×βνkr ( ξ) ikr i2iω( k )( t −ihλ)⎡ ⎤ ∑ ⎡h∫k0 k× 1 + N ( β) ⎤⎦ e⎣V , e⎦V () t − dλ V⎣e Nk( β)+( β )+ e 1 + N ( ) ⎤ e ⎡V , e ⎤ V (), t− iω ( k )( t − i h λ ) − ( − h )⎦ ikr t i λ⎣ ikrkν ⎦ µ−{(3.4)iLtsa<strong>da</strong>c: V () t = e V (0) ,µ µiiΤΡ ( ) ξ − Τ ( Ρ)ξ rh h iLsξr( ξ ) = e re ≡e r <strong>da</strong> r ( ξ ) aris eleqtronis TavisufalimoZraobis “traeqtoria”. analogiurad Caiwereba kinetikuriµ νgantoleba V (0) V ( − t)korelaciuri funqciisTvis. (3.4) gantolebis gamoyvanisasCven visargeblebT agreTve Semdegi TanafardobebiT: ω( − k) = ω( k);V= V .− k kCven SemovifarglebiT mxolod erTi zonis miaxloebiT eleqtronisTvis,rodesac eleqtronis siCqaris operatori diagonaluriaimpulsur (kvaziimpulsis) warmodgenaSi <strong>da</strong> amitom adgili aqvs Semdegtolobebs:∂( Ρ ) = ΤΡ ( );∂ΡV µµ⎡⎣V µ( Ρ), ΤΡ ( ) ⎤⎦ = 0, ( µ = xyz , , ).Cven viyenebT agreTve aRniSvnas V µ( Ρ ) eleqtronis siCqaris operatorismatriculi elementisTvis ΡV µΡ , romelic gamoiTvleba eleqtroniskvaziimpulsis operatoris sakuTari funqciebis Ρ meSveobiT.−110


Tu SemoviRebT Semdeg relevantur (<strong>da</strong>mxmare) operators (Se<strong>da</strong>rebisTvisix. (2.39)) Gµ (, t β ); sawyisi mniSvnelobiT, rodesac t = 0;Gµ ( β) = Gµ(, t β )t =0<strong>da</strong> ganvsazRvravT tolobebiT:G t = Z S Ρ ⎣V te β H⎦−1(, β) ( β) ⎡ −() ⎤ ;µ Σ µsZ ( β)Gµ ( β) = Vµ,(3.5)S ZsΡ ⎡ ⎣( β)⎤ ⎦ssHsa<strong>da</strong>c: Z ( β ) = S Ρ ⎡ −e β ⎤Σ ⎣ ⎦- <strong>da</strong>yvanili (reducirebuli) statjamia eleqtronfononurisistemisTvis; maSin SemoRebuli (3.5) operatoris <strong>da</strong>xmarebiTSesaZlebelia V (0) V ( ± t)- korelaciuri funqciebi <strong>da</strong> maTi Sesabamisiν µkinetikuri gantolebebi gamovsaxoT Semdegi formiT:∂∂tVν (0) Vµ ( ± t) = SΡ s⎡⎣Vν (0) Gµ( ± t, β ) ⎤⎦⎡ ∂ ⎤V (0) ( ± ) ≡ Ρ ⎢ (0) ( ± , ) ⎥=± Ρ ⎡⎣ (0) Γ ( ± , ) ( ± , ) ⎤νVµ t SsVν Gµ t β SsVν νt β Gµt β ⎦,⎣ ∂t⎦(3.6)sa<strong>da</strong>c: operatori Γ (, t β)uSualod ganisazRvreba (3.4) gantolebi<strong>da</strong>n <strong>da</strong> aqvsSemdegi saxe:0ν{t12 −iω( k ) ξ iω( k) ξ−1Γ (, ) =− ⎡ ( ) +2 ∫ ∑( 1 + ( ))⎤νt β dξ V⎣e N β e N β⎦V ×k k kνh( β )⎡ ⎤ ⎡ ⎤ikr −ikr ( ξ) iω( k ) ξ −iω( k ) ξ −1 −ikr( ξ )×⎣V , e⎦e − ( ) + 1 + ( ) ×− ⎣e N β e Nkk ⎦V eννβi2 ω( )( − hλ) −νω( )( − hλ)} ∫ λ∑βk k( βk)ikr i k t i k t i× ⎡ , ⎤ − ⎡ ( ) + 1 + ( ) ⎤⎣Vνe⎦d V ×− h⎣e N e N⎦× Vikre ⎡ , ⎤⎣Vνe⎦,−1 − ikr ( t − i hλ)ν0kk−(3.7)sa<strong>da</strong>c:V ⋅ V = V ⋅ V = 1.−1 −1ν ν ν ν(3.6) kinetikur gantolebebSi kvali eleqtronis (qvesistemis) mdgomareobebismixedviT gamovTvaloT eleqtronis kvaziimpulsis operatorisΡ sakuTari funqciebis saSualebiT. amis gaTvaliswinebiT (4.6)Tanafardobebi SesaZlebelia CavweroT Semdegi saxiT:V (0) V ( ± t) = dV Ρ ( Ρ ) G ( ± t, β, Ρ)∫ν µ ν µ∫∂dV Ρ ( Ρ ) G ( ± t, β, Ρ ) =± dV Ρ ( ΡΓ ) ( ± t, β, Ρ ) G( ± t, β, Ρ).ν µ ν ν µ∂t∫(3.8) gantolebebis miRebisas Cven gaviTvaliswineT, rom eleqtronissiCqaris operatori diagonaluria kvaziimpulsis warmodgenaSi <strong>da</strong>, vinai<strong>da</strong>nganixileba sivrculad erTgvarovani sistema, amitom mxolod diagonaluri(3.8)111


matriculi elementebi – ΡΓ (, t β) Ρ ≡Γ (, t β , Ρ); Γ (, t β)- operatoris arisνgansxvavebuli nulisagan. Tu visargeblebT Semdegi TanafardobebiT:ν± ikre δ ( hk)ikrikr( Ρ ) = ( Ρmh) ;± ikr ± ikr( Ρ ) = ( Ρ± h ),Ρ Ρ = Ρ ± −Ρ1 2 2 1 ;e f f k e± ±f e e f ksa<strong>da</strong>c: f ( Ρ ) warmoadgens Ρ kvaziimpulsis (impulsis) nebismier funqcias <strong>da</strong>visargeblebT (3.7) gantolebiT, maSin Γν (, t β ) operatoris Γν(, t β, Ρ ) matriculielementisaTvis miviRebT Semdeg gantolebas [120]:ν⎧ ⎡t− ⎤sin ( , )2 2 ( ) ( )⎢∆ k ΡV ⎥νΡ+ hk −VνΡ ⎪(, , ) ( )⎣hΓ⎦νt β Ρ = ∑ V ⎨Nβ+kk−h k Vν( Ρ) ⎪ ∆ ( k, Ρ)⎪⎩⎡t+ ⎤sin ( , )−⎢ ∆ k Ρ ⎥ i⎡− −β∆( k , Ρ)− ∆ ( , Ρ)1( 1 ( )⎣h⎦ it k e −h+ + N β )+ ( )++ ⎢N β ekk−∆ ( k, Ρ) 2 ⎢⎣∆ ( k, Ρ)+i + −β∆( k , Ρ)− t∆ ( k, Ρ)e −1⎤⎫⎪+ ( 1 + N ( β )h) e,k+ ⎥⎬∆ ( k , Ρ)⎥⎪ ⎦⎭(3.9)±sa<strong>da</strong>c: ∆ ( k, Ρ ) =ΤΡ+ ( hk) −ΤΡ± ( ) h ω( k).ganvixiloT axla izotropuli SemTxveva, rodesac eleqtrogamtarobistenzors <strong>da</strong> simetrizebul korelaciur funqcias aqvT Semdegnairisaxe:ssssσ ( ω) = σ ( ωδ ) ; Ψ () t =Ψ () t δµν µνµν µν<strong>da</strong> visargebloT miaxloebiTi gantolebiT, romelic gamomdinareobs (3.8)gantolebi<strong>da</strong>n:∂Gµ ( ± t, β, Ρ ) =±Γµ( ± t, β, Ρ ) Gµ( ± t, β, Ρ).(3.10)∂tcxadia, rom (3.10) kinetikuri gantoleba warmoadgens relaqsaciisdrois miaxloebis (rdm) saxis aproqsimacias. naTelia, rom (3.10) miaxloebiTigantoleba xdeba zusti, rodesac Γ ( ± t, , Ρ ) funqcia ar arisµβ<strong>da</strong>mokidebuli Ρ kvaziimpulsze. magaliTad, aseT SemTxvevas aqvs adgilifrolixis polaronisTvis <strong>da</strong>bali temperaturebis areSi [116-118, 120].Tu CavatarebT (3.10) gantolebis integracias <strong>da</strong> gaviTvaliswinebT (3.5)sawyis pirobebs, maSin Cven miviRebT:112


~ r r[ Γ ( t,β , P] G ( β,);rG ( ± t,, P)= expP Γ~ tr( t,, P)= ∫dτΓ( τ , β,Pr)µβµ±µµβµ;0sV ( Ρ) Z ( β, Ρ)µssGµ ( β, Ρ ) = Ρ Gµ( β) Ρ = ; Z ( β, Ρ ) = Ρ Z ( β) Ρ .sdΡZ( β, Ρ)∫(3.11)Tu CavsvamT Γ (, t , Ρ)-s (3.9) mniSvnelobas (3.11) formulaSi, maSinµβintegraciis Sedegad Γ% (, t , Ρ)-Tvis Cven miviRebT gamosaxulebas:µβΓ% (, t β, Ρ ) = Re Γ% (, t β, Ρ ) + iIm Γ%(, t β, Ρ);µ µ µV ( Ρ+ hk) −V( Ρ)Re Γ (, t β, Ρ ) = ∑ V N ( ) ⎡1+ e ⎤×µk⎦k2 −µ µ −β∆( k , Ρ)βkV ( Ρ)⎣µ{⎡t− ⎤ ⎡t+ ⎤⎫1−cos ⎢ ∆ ( k , Ρ) ⎥ 1− cos ⎢ ∆ ( k, Ρ)+⎣h⎦⎥− ∆ ( , Ρ)2 ( 1 ( ))⎡β k⎪1 ⎤ ⎣h× + + N β +⎦;2 ⎬− ⎣e⎦(3.12)k+⎡⎣∆ ( k , Ρ) ⎤⎦⎡⎣∆ ( k, Ρ)⎤⎦ ⎪⎪⎭( , )2 ( ) ( ) ⎧−−β∆k ΡΡ+ − Ρ ⎪ 1−Im Γ%V hk Vµ µe(, t β, Ρ ) =− ∑ V ⎨ N ( β )×µkk2( ) −kVµΡ ⎪ ⎡ ( , ) ⎤⎩ ⎣∆k Ρ ⎦+−β∆( k , Ρ)− 1−⎫+ ⎪× sin⎡t ∆ ( , Ρ )⎤ e+ ( 1 + ( ))sin⎡t∆ ( , Ρ) ⎤⎢k⎥N β.k+2 ⎢k⎥⎬⎣h⎦ ⎡⎣∆ ( k , Ρ)⎤⎦⎣h⎦⎪⎭(3.11) <strong>da</strong> (3.12) gamosaxulebebi asaxaven (3.6) korelaciuri funqciebisdroze <strong>da</strong>mokidebulebas <strong>da</strong> principSi saSualebas iZlevian, rom gamoTvliliqnes eleqtrogamtarobis tenzori (3.2)-(3.3) formulebis <strong>da</strong>xmarebiT.vinai<strong>da</strong>n Cven SemovifarglebiT SeSfoTebis Teoriis mxolod meoremiaxloebiT (3.4) kinetikur gantolebaSi eleqtron-fononuriurTierTqmedebis ( )H V hamiltonianis mixedviT, amitom Tanmimdevrobisik−βH−β 0 s<strong>da</strong>cvis mizniT SevasruloT miaxloeba: e e H −β e H −βeH Σ⇒ = - korelaciurifunqciebis (3.5)-(3.11) – sawyisi mniSvnelobebisaTvis. Aamrigad Cven gvaqvs:−βHs−βΤ( Ρ)eeGµ ( β) = V ; G ( , ) V ( ).H µ µβ−βs−βΤ( Ρ)µSΡ⎡e ⎤Ρ = sdΡeΡ(3.13)⎣ ⎦ ∫(3.8), (3.11) <strong>da</strong> (3.13) gantolebebs mivyavarT Semdeg gamosaxulebamdeΨ () t korelaciuri funqciisaTvis:µν∫{ ⎡% β ⎤ ⎡%β ⎤}2−βΤ( Ρ)e dΡe Vν ( Ρ) Vµ ( Ρ) exp ⎣Γν (, t , Ρ ) ⎦+ exp ⎣Γµ( −t, , Ρ)⎦Ψµν() t =,−βΤ( Ρ)2dΡe∫(3.14)113


sa<strong>da</strong>c: Γ % (, t β, Ρ)<strong>da</strong> Γ% ( −t, , Ρ ) ganisazRvrebian (3.12) formulebiT.νµβ(3.12) <strong>da</strong> (3.14) tolobebis Tanaxmad, eleqtronis (qvesistemis) korelaciurifunqciebi miilevian oscilaciebiT imis gamo, rom relaqsaciisΓ % (, t β, Ρ)-faqtori warmoadgens kompleqsur sidides, <strong>da</strong> rogorc CvenνmogvianebiT vaCvenebT, es oscilaciebi “sicocxlis unariani” arian dididroebis asimptotur areSi t >> t0<strong>da</strong> iZlevian wvlils ga<strong>da</strong>tanis kinetikurkoeficientebSi (eleqtrogamtaroba, Zvradoba) [117-118, 120-122]. es <strong>da</strong>skvnagamomdinareobs im martivi garemoebi<strong>da</strong>n, rom wonasworuli droiTikorelaciuri funqciebis gansazRvrebaSi (ix. mag. (2.6) formula) figurirebsgibsis ganawileba, romelic Seicavs sawyisi korelaciebis wevrs ( Hint ) <strong>da</strong>romlis zusti gaTvaliswinebac xdeba evoluciur (kinetikur) gantolebebSiam funqciebisTvis. Sfm-Si Γ (, t β, Ρ ) _ relaqsaciis faqtoris warmosaxviTiνnawili nulis tolia, <strong>da</strong>, amitom zemoT miTiTebul oscilaciebs adgili areqneba [75,77]. un<strong>da</strong> aRiniSnos, rom ganxiluli msjeloba samarTliania imSemTxvevaSi, rodesac adgili aqvs droTa ierarqias (ix. (2.34) formula);rogorc (3.12) formuli<strong>da</strong>n naTlad Cans, im SemTxvevaSi, rodesac ganixilebaeleqtronis urTierTqmedeba fononebTan: t ~ hβ<strong>da</strong>stΣ~1ϖ, sa<strong>da</strong>c ω - warmoadgensfononTa maxasiaTebel sixSires. ufro metic, (3.12)gamosaxulebi<strong>da</strong>n gamomdinareobs, rom energiis Senaxvis kanoni eleqtronisfononebTan gabnevis procesis dros samarTliania didi droebisSemTxvevaSi: t0t >> , t ( )0= max ts,t Σ; Tu ganvixilavT droTa did intervalst >> t 0, maSin Cven SegviZlia SevasruloT zRvruli ga<strong>da</strong>svla t →∞ (3.12)gamosaxulebaSi <strong>da</strong>, rogorc Sedegi miviRebT [120]:1limRe Γ%relν(, t β, Ρ ) =−Γν( β, Ρ ) t =− t ;t→∞relτ ( β, Ρ)rel 2π2 Vν( Ρ+ hk) −Vν( Ρ)−Γ ( , Ρ ) =− ∑( ) ⎡∆ ( , Ρ ) ⎤νβV N βδ +kkh( Ρ)⎣ kV⎦+( N β ) δ ⎡ k ⎤k}+ 1 + ( ) ⎣∆ ( , Ρ) ⎦ ;kν2 ( Ρ+ ) − ( Ρ)−limIm Γ%Vνhk Vν(, , ) ( ) ⎡ ( , ) ⎤νt β Ρ =−βπ∑V N βδ ∆ Ρ +t→∞kk( Ρ)⎣ k ⎦k Vν++ ( 1 + N ( β)k ) δ ⎡⎣∆( k, Ρ) ⎤⎦}Signt.{{(3.15)(3.15) formulebis gamoyvanisas Cven visargebleT TanafardobebiT:114


1−cos( ωt) sin( ωt)lim = π t δω ( ); lim = πδ( ω) Signt.t→∞2ωt→∞ωaRvniSnavT, rom (3.15) gamosaxulebebSi limt→∞Sesruldes Termodinamikuri zRvruli ga<strong>da</strong>svla (Τ -zRvari):V... dk (...).(2 π)∑( ) =3 ∫kzRvrul ga<strong>da</strong>svlamde un<strong>da</strong>cxadia, rom Zalian didi droebis asimptotur areSi, rodesac( t >> t , t → ) (3.15) Tanafardobebi Cven gvaZlevs Semdeg tolobas:0∞1limIm Γ % (, , Ρ ) = Γ ( , Ρ) .→∞2h relνt β βνβ Signt(3.16)tνrelamrigad, Γ ( β, Ρ ) - sidide, romelic faqtiurad warmoadgens eleqtronis“siCqare-siCqare” – korelaciuri funqciis milevis dekrements –SesaZlebelia ganxilul iqnas rogorc eleqtronis V ν( Ρ ) siCqaris ? –relkomponentis relaqsaciis sixSire ( τ ( β, Ρ)- warmoadgens Sesabamisrelaqsaciis dros).<strong>da</strong>bolos, Tu visargeblebT (3.2)-(3.3) <strong>da</strong> (3.14)-(3.15) TanafardobebiT,sabolood vpoulobT gamosaxulebas kuTri eleqtrogamtarobisdisipaciuri nawilisTvis [120]:⎛1⎞th⎜βhω2⎟⎝ ⎠ r⎧ ⎡βh⎤= ∫ Ρ Ρ Ρ Ρ ⎨ ⎢Γ Ρ ×hω⎣ 2 ⎥⎩⎦s 2relRe σµνne d ρs( β, ) Vν ( ) Vµ ( ) cosν( β, )relrel( , )⎫Γ ( , )Γ Ρνβ Ρ ⎡βhrel ⎤ µβ ⎪× + cos Γ ( , Ρ) ,22 ⎢ µβ22⎬rel( , ) ⎣ 2 ⎥relω + ⎡Γ Ρ ⎤ ⎦⎣ ⎦ + ⎡⎣Γ ( , Ρ)⎤νβ ωµβ ⎦ ⎪⎭ν(3.17)sa<strong>da</strong>c: n - warmoadgens <strong>eleqtronebis</strong> koncentracias gamtarobis zonaSi,−βΤ( Ρ) −βΤ( Ρ)xolo ρ ( β, Ρ ) = e dΡe.s ∫ releqtronis <strong>da</strong>baltemperaturuli Zvradoba, romelic <strong>da</strong>mokidebuliagareSe eleqtruli velis ? sixSireze (ac-mobility), SesaZlebeliawarmodgenili iqnas Semdegi saxiT (saubaria dreiful Zvradobaze):sa<strong>da</strong>c:µω ( ) = µ ( ω ) −∆ µω ( ),0µ⎛ 1 ⎞eth⎜βhω⎟⎪⎧rrrelΓ ⎪⎫⎝ 2 ⎠r r r rrelΓ ( , )( , P)Vβ Pµβω)= ∫dPρs(β,P)VV( P)Vµ( P)⎨r +⎬;2 rel2rhω2 rel⎪⎩ ω + [ ΓV( β,P)] ω + [ Γµ( β,P)] ⎪⎭0( 2115


⎛ 1 ⎞2eth⎜βhω⎟∆ =⎝ 2 ⎠r r r rµ ( ω)∫ dPρS(β,P)VV( P)Vµ( P)×(3.18)hω⎪⎧rrrelrel2( , )2( , ) ⎪⎫⎡βhrrel ⎤ Γ⎡⎤ Γ⎨sin ( , )2sin ( , )2 ⎬;42⎢[ ( , )] 4 ⎥ ⋅ PVβ P βhrrelµβ−1× ⎢ ΓVβ P ⎥r + Γµ β Pr ( ω


3.2. eleqtronis Zvradoba frolixis polaronis modelSi3(“2βhω0problema” polaronis <strong>da</strong>baltemperaturuliZvradobis TeoriaSi)ganvixiloT axla eleqtroni, romelic moZraobs polarul naxevargamtarSian ionur kristalSi, romlis moZraoba aRiwereba (1.13)-(1.18)hamiltonianiT <strong>da</strong> romelic sustad urTierTqmedebs polarul optikurfononebTan: ( α < 1) (e.w. frolixis polaronis modeli) [29-30]. ganixilebaeleqtronis urTierTqmedeba dispersiis armqone optikur fononebTan,rodesac ω( k ) ≡ ω0. vinai<strong>da</strong>n eleqtronis energiisTvis gamtarobis zoni<strong>da</strong>nrr2Ρgvaqvs gamosaxuleba ΤΡ ( ) = , amitom eleqtronis siCqaris µ -2mkomponentisTvis gveqneba Semdegi formula:r ΡµVµ( Ρ ) =m(3.19)rogorc (3.14), (3.15) <strong>da</strong> (3.17) gamosaxulebebi<strong>da</strong>n Cans, sakiTxi <strong>da</strong>iyvanebareleleqtronis relaqsaciis sixSiris: Γ ( , Ρ r )- gamoTvlaze, romelic zogadµβSemTxvevaSi <strong>da</strong>mokidebulia eleqtronis Ρ r impulsze.<strong>da</strong>vuSvaT, rom eleqtruli veli mimarTulia z RerZis <strong>da</strong>debiTi mimar-relTulebis gaswvriv, <strong>da</strong>, gansazRvrulobisaTvis ganvixiloT Γ ( β, Ρ r ). TuSevasrulebT Termodinamikur zRvrul ga<strong>da</strong>svlas <strong>da</strong> CavatarebTintegracias k rcvladis mixedviT, maSin (1.18) <strong>da</strong> (3.15) gamosaxulebebi<strong>da</strong>nmiviRebT:2ππ~ αω ⎪⎧0( β,Ρ)= ~ 1⎨Ν0(γ ) dϕdθsin θ cosθ2πΡz⎪⎩ 0 0relΓ0∫ ∫~Ρ cos Φ~+2 2Ρ cos Φ + 12ππ~Ρ cosΦ⎫ ~ 2 2+ ( 1+ Ν ( γ )) ∫ d ϕ∫ dθsin θ cosθ⎬(Ρ cos Φ ≥ 1 ).0 ~(3.20)2 20 0Ρ cos Φ −1⎭aq Cven SemoviReT eleqtronis uganzomilebo impulsi:~ ΡiΡi = ; i =2mhω0( x,y,z)<strong>da</strong>10e γ −γ = ⎡ − ⎤ γ = βhω0N ( )⎣1⎦; .Φ - warmoadgens kuTxes k r <strong>da</strong> Ρ ~ veqtorebs Soris, romelic <strong>da</strong>kavSirebuliaθ <strong>da</strong> ϕ kuTxeebTan (θ <strong>da</strong> ϕ kuTxeebi gansazRvraven k r veqtoriszmimarTulebas) Semdegi TanafardobiT:117


~Ρ cosϕ~= sin θ cosϕΡx~+ sin θ sin ϕΡy~+ cosθΡ.z(3.20) gamosaxulebis gamosaTvlelad SemovisazRvroT <strong>da</strong>balitemperaturebis SemTxveviT, rodesacγ >> 1(3.21)<strong>da</strong> (3.14) korelaciuri funqciebi gansazRvrulia eleqtronis impulsismcire mniSvnelobebiT:~Ρ 2> ).(3.24)ω 0(3.24) gamosaxulebis gamoTvlisas Cven visargebleT SemdegiformulebiT:∫r~dPe3~r2~ r2 ~r~2−γP2 1 ⎛π⎞−γPPz⎜ ⎟ ; dPe=2γ∫⎝ γ ⎠⎛ π= ⎜⎝ γ32⎞⎟⎠(3.25)amrigad, rogorc (3.24) gamosaxulebi<strong>da</strong>n Cans, eleqtronis “siCqaresiCqare”korelaciuri funqciebi eqsponencialurad miilevian drois mixedviT<strong>da</strong>bali temperaturebis ganxilul SemTxvevaSi. (3.24)-is Tanaxmadrelrelrelaqsaciis droisTvis gveqneba Semdegi gamosaxuleba: τ ( γ) = ⎡ ⎣Γ0( γ) ⎤ ⎦.−1118


cxadia, rom Cvens mier miRebuli rezultati napovnia Sfm-isgamoyenebis gareSe [120]. (3.24) gamosaxuleba gansxvavdeba Sedegisagan, romel-⎡ iγ rel⎤ic napovnia Sfm-Si [77] eqsponencialuri faqtoriT exp ⎢± Γ0( γ ) .2ω⎥⎣ 0 ⎦gamovTvaloT axla eleqtrogamtaroba <strong>da</strong> <strong>da</strong>baltemperaturuliZvradoba eleqtronisTvis frolixis polaronis modelSi susti eleqtronfononuriurTierTqmedebis dros: ( α < 1). Tu gaviTvaliswinebT (3.19) <strong>da</strong>(3.23)–(3.25) gamosaxulebebs, (3.17) formuli<strong>da</strong>n kuTri eleqtrogamtarobisTvismiviRebT [120]:2~ ne 2 ⎛ 1 ~ ⎞⎡( ))2⎛γ⎞⎤Γ0γRe σ ( ω = ~ th⎜γω⎟1 2sin0() ~ ;2 202⎢ − ⎜ Γ γ ⎟mωγω2⎥⎝ ⎠⎣⎝ ⎠⎦ω + Γ0( γ)( α < 1, γ >> 1, ωγ ~ > 1, ω~γ t0pirobi<strong>da</strong>n) <strong>da</strong> γ . Γ0 ( γ )


mcire sidideebs ( γ >> 1). (3.27) gamosaxulebebi<strong>da</strong>n eleqtronis<strong>da</strong>baltemperaturuli statikuri ZvradobisTvis (dc-mobility) frolixispolaronis modelSi gveqneba [120]:µ0e=mω0Γ−10( γ ) =emω32α2e2⎡γ⎤∆µ= sin⎢Γ0( γ ) Γmω0⎣ 2 ⎥⎦( γ >> 1, α < 1).0−10eγ;e( γ ) =mω01 2αγ e3−γ;(3.28)napovni (3.28) gamosaxulebebi warmoadgens Tanamimdevrul <strong>da</strong> sworrezultats eleqtronis <strong>da</strong>baltemperaturuli Zvradobisa, frolixispolaronis modelSi, mcire temperaturuli SesworebiT susti eleqtronfononuriurTierTqmedebis SemTxvevaSi [114-118,120].ganvixiloT axla eleqtronis gamtaroba <strong>da</strong> Zvradoba polaronisfrolixis modelSi eleqtruli velis maRali sixSireebis SemTxvevaSi,rodesac adgili aqvs Semdeg Tanafardobas:rrel−1Γ ( β,Ρ)


gamovTvaloT axla (3.32)-is <strong>da</strong>xmarebiT <strong>eleqtronebis</strong> kuTri eleqtrogamtaroba<strong>da</strong> Zvradoba eleqtruli velis maRali %ω -sixSireebis Sem-TxvevaSi. vipovoT jer σ ( %)0ω -kuTri eleqtrogamtarobis mniSvneloba. TurelCavsvamT Γ ( β, Ρ r )-s (3.32) gamosaxulebas (3.30)-is pirvel formulaSi,CavatarebT martiv gar<strong>da</strong>qmnebs <strong>da</strong> gamoviyenebT (3.19) <strong>da</strong> (3.31) formulebs,maSin Ρ r -impulsuri cvladiT integraciisa <strong>da</strong> Termodinamikuri zRvruliga<strong>da</strong>svlis Semdeg, σ 0( ω%)-eleqtrogamtarobisTvis miviRebT Semdeg gamosaxulebas:2neσ ( ω% ) = σ%( ω%);0 0mω0∞2 2 1 2 3210( )⎛ ⎞ ⎡ γωσ % % ω% = th0( )⎛ ⎞⎜ γω%2⎟ αγ N γ3∫dk⎢e ⎜k+ ×γω%⎟⎝ ⎠ π0 ⎣ ⎝ k ⎠2 2γ ⎛ 1 ⎞ γ ⎛ 1 ⎞− ⎜k+ ⎟4 1− ⎜k−⎤⎟⎝ k ⎠ ⎛ ⎞ 4⎝ k ⎠× e + ⎜k− ⎟e⎥; Re σ0( ω% ) ≡σ0( ω%),⎝ k ⎠ ⎥ ⎦(3.33)sa<strong>da</strong>c: σ% 0( ω% ) warmoadgens uganzomilebo dinamiur (sixSireze <strong>da</strong>mokidebul)gamtarobas, xolo uganzomilebo parametrebi: γ , ω% <strong>da</strong> N 0( γ ) moicema (3.20) <strong>da</strong>(3.26) formulebiT. SevniSnoT, rom sixSireze <strong>da</strong>mokidebul eleqtroniseZvradobisaTvis (3.33)-is msgavsad gveqneba: µ0( ω %) = µ %0( ω%) <strong>da</strong> µ % 0( ω% ) ≡ σ%0( ω %).mωeleqtronis dinamiuri gamtarobisTvis miRebuli (3.33) gamosaxulebafrolixis polaronis modelSi SesaZlebelia CavweroT kompaqturi formiT,Tu CavatarebT integracias k -cvladiT (3.33) gamosaxulebaSi. gveqneba:02 1 2γ2 32 2ωσ % %10( ω% ⎛ ⎞ ⎛ ⎞) = th γω αγ eN0( γ) K1γ ,γω⎜ %% 2⎟ ⎜3 π2⎟⎝ ⎠ ⎝ ⎠sa<strong>da</strong>c: K 1() z warmoadgens pirveli gvaris makdonaldis funqcias.(3.34)(3.32) formula saSualebas iZleva, rom gamoTvlili iqnas eleqtronisimpulsis relaqsaciis sixSire, k r -cvladiT integraciis Semdeg. (3.32)relgamosaxuleba: Γ ( β, Ρ r )-sididisTvis miiRebs Semdeg saxes:⎧~ ⎡ ~~ ⎤ ⎡ ~~ ⎤⎫Γ Ρ = ~ 1⎨ + Ν Ρ −⎢Ρ − + ~ 1 Ρ⎥+ Ν⎢Ρ + − ~ 1rel ~220( γ , ) ω0α(10(γ ) θ(1) 1 arcch0(γ)1 arcshΡ2⎥⎬Ρ ⎩⎣ Ρ ⎦ ⎣ Ρ ⎦⎭(3.35)121


cxadia, rom eleqtronis impulsis mcire mniSvnelobebisaTvis, rodesac:Ρ


~Γ1). Se<strong>da</strong>rebiT <strong>da</strong>bal sixSiruli are, rodesac:~1( γ , Ρ)


32−2it−ittS t)= D ( t)[(1+ N ( γ )) e + N ( γ ) e ]; <strong>da</strong> D(t)= − it;(3.41)γ(00Ffxip-is TeoriaSi (miaxloebaSi) eleqtronis dreifuli ZvradobaMmoicema (ganisazRvreba) Semdegi TanafardobiT:1µ ~FXIP~ 2~= lim Re ~ ( ~ ) lim Re ( ~~ ω σ ω ~ Z ω );(3.42)ω → 0=ω →0sa<strong>da</strong>c: (3.40)-formulis Tanaxmad, eleqtronis impen<strong>da</strong>nsis realuri nawiliganisazRvreba Semdegi tolobiT:3 1~ ~ 2αsin( ω~ t412 2=~ )γRe Z ( ω)dt Im[ S(t)] = αγ e N0(γ)K1(γ ). ( ω ~ → 0)(3.43)3 π ω3 π2∞∫0(3.43)-gamosaxulebi<strong>da</strong>n martivad miiReba eleqtronis <strong>da</strong>baltemperaturulistatikuri ( ω = 0)dreifuli Zvradobis mniSvneloba ( ix. Se<strong>da</strong>rebi-saTvis (3.37)-formula) fxip-is miaxloebaSi:3 1 γµ = FXIPe ;2γ2α( γ >> 1, γ → ∞)(3.44)Bbalansis gantolebis meTodze <strong>da</strong>yrdnobiT tornberg-feinmanis miermiRebuli eleqtronis statikuri dreifuli Zvradobis mniSvneloba moicemaSemdegi gamosaxulebiT: [ 53, 84-85, 101-103 ];31241~ 1 α∞ γ2 2= Im[ ( )] αγ0(γ )1(γ)µ 3 π∫dt⋅t⋅ S t = e N K(3.45)3 π2TF0romelic emTxveva fxip-is mier miRebul dreifuli Zvradobis (3.43)-mniSvnelobas.Aamitom cxadia, rom frolixis polaronis (eleqtronis)<strong>da</strong>baltemperaturuli ZvradobisTvis gvaqvs igive saxis gamosaxuleba,rogoric fxip-is TeoriaSi:~ 3 1 γµ = e ;( γ >> 1, γ → )2γ2α∞TF(3.46)[ 15 ] - naSromSi gamokvleuli <strong>da</strong> naCvenebi iyo, rom tornberg-feinmanismidgomaSi eleqtronis dreifuli Zvradobis gamoTvlisas gamoiyenebo<strong>da</strong>maqsvelis wanacvlebuli ganawilebis funqcia eleqtronisaTvis; xolofxip-is TeoriaSi eleqtronis Zvradobis gamosaTvlelad gamoiyenebaeleqtrogamtarobis (eleqtrowinaRobis) mniSvneloba SeSfoTebis Teoriismeore miaxloebaSi. (α -bmis mudmivas rigis mixedviT).rogorc aRniSnuli iyo literaturis mimoxilvaSi, frolixis polaronis<strong>da</strong>baltemperaturuli Zvradobis gamosaTvlelad mravali gamokvleva124


iqna Catarebuli bolcmanis kinetikur gantolebaze <strong>da</strong>yrdnobiT [ 55, 91, 93,98 ]. aRniSnuli gamokvlevebis Sedegad miRebuli <strong>da</strong>baltemperaturuliZvradobis mniSvneloba moicema Semdegi gamosaxulebiT:~ 1 γµ = Be ; ( ω ~ =2α0, γ >> 1; γ → ∞ )(3.47)(3.47)- formulis miRebis dros, bolcmanis gawrfivebuli (gareSe eleqtrulivelis mixedviT) kinetikuri gantolebis amoxsnisas gamoiyenebo<strong>da</strong>relaqsaciis drois miaxloeba <strong>da</strong> Tanac <strong>da</strong>jaxebiT integralebSi ga<strong>da</strong>svlissixSireebis <strong>da</strong> TviT integralebis gamoTvlisas gaTvaliswinebuliiyo mxolod “<strong>da</strong>naklisis” wevrebi. Aam miaxloebebis farglebSi -eleqtronis ganawilebis funqciis relaqsaciis sixSirisaTvis (droisTvis)miiRebo<strong>da</strong> Semdegi saxis gamosaxuleba:Γr+ rr− r{(1+ N ( β )) δ [ ∆ ( k , p)],+ N ( β ) δ [ ∆ ( k,p ]}β r 1 2π2, p ) = =rel r ∑ V)2 K0τ ( β , p)h(3.48)relB(0BK(Se<strong>da</strong>rebisTvis ix. (3.31) formula).~sai<strong>da</strong>nac, mcire siCqareebiT moZravi eleqtronisaTvis Ρ 2> 1),Tu CavatarebT martiv ga-moTvlebsdgindeba, rom relaqsaciis sixSire Γ Ρ~ rrelB( γ , ) − warmoidgineba Semdegi formiT:~rrel~Γ γ , Ρ)= Γ ( γ ) 2αN( ); ( γ >> 1, Ρ 2


~ ~1sazRvrebs: Γ rel ( , ) ~0γ Ρ


Vν( p + hk) − VνrV ( p)νr( p)(ix. (3.9),(3.12), (3.15)), romelic aRwers eleqtronissiCqaris cvlilebas misi gabnevisas fononebze, maSin rodesacrel releqtronis ganawilebis funqciis relaqsaciis sixSire: Γ ( β,p)(ix. (3.48))-aseTi saxis Tanamamravls ar Seicavs. swored es faqtori ganapirobebs am<strong>da</strong>matebiTi mamravlis warmoqmnas [120]. rac Seexeba fxip-isa <strong>da</strong> tornbergfeinmanisSedegebis Tanxvedras ~ 1 3 γµFXIP= µTF= e ; ( γ >> 1) <strong>da</strong>2γ2αmamravls, maTi warmoSobis buneba dRevandel dRemde bolomde garkveuliar aris.B12γ-3.3. eleqtronis Zvradoba akustikuri polaronismodelSi susti eleqtron –fononuri urTierTqmedebis SemTxvevaSiganvixiloT eleqtroni, romelic moZraobs kovalentur (araionur)kristalSi an naxevargamtarSi, romlis moZraoba aRiwereba (1.13)-(1.14) hamiltonianiT.<strong>da</strong>vuSvaT, rom eleqtroni sustad urTierTqmedebs akustikur2 2D mfononebTan; α = < 1. Aam SemTxvevaSi adgili aqvs eleqtronis38πρhV srrurTierTqmedebas dispersiis mqone akustikur fononebTan: ω ( k ) = V k;k ≡ k .eleqtronis energiisaTvis gamtarobis zoni<strong>da</strong>n gvaqvs dispersiisstan<strong>da</strong>rtuli paraboluri kanoni <strong>da</strong> eleqtronis siCqariss⋅µ −komponentimoicema (3.19) formuliT. eleqtronis Zvradobis gamosaTvlela<strong>da</strong>kustikuri polaronis modelSi visargebloT (3.17)–(3.18) formulebiT,rel rxolo Γ ( β,p)- relaqsaciis sixSiris gamosaTvlelad ki – (3.15)vacgamosaxulebiT. Tu gamoviyenebT (1.14) <strong>da</strong> (3.15) – formulebs, mivmarTavTeleqtrul velsΖ − RerZis <strong>da</strong>debiTi mimarTulebis gaswvriv, SevasrulebTTermodinamikur zRvrul ga<strong>da</strong>svlas <strong>da</strong> CavatarebT integrebas K-cvladiT,rrelmaSin Γzac( γ , Ρ)− relaqsaciis sixSirisaTvis miviRebT gamosaxulebas:Γrelzacr~ mV( γ,Ρ)= −h2s16α~Ρz∫dΩrk~cosθ(1 −ΡcosΦ)3exp1~[ 4γ(1−ΡcosΦ)]2mV− 16 sα~1~ ∫ d Ω r cosθ(1+ ΡcosΦ)3;kh Ρexp−1z~[ 4γ(1 +ΡcosΦ)]( α < 1.)−−1(3.50)127


sa<strong>da</strong>c:2mVsγ = - warmoadgens modelis maxasiaTebel uganzomilebo fi-2KT −zikur parametrs,B~rΡ −uganzomilebo impulsia:~ rΡ = Ρ / mVs~~~ ~dΩ r k= sin θdθdϕ;Ρ cosΦ = sin θ cosϕΡ+ sin θ sin ϕΡ+ cosθΡ,sa<strong>da</strong>c θ <strong>da</strong> ϕ - sferuli kuTxeebia, xolo Φ - warmoadgens kuTxesK r <strong>da</strong> Ρ rveqtorebs Soris. gamovTvaloT (3.50) – formulis <strong>da</strong>xmarebiTeleqtronis impulsis relaqsaciis sixSire kristalis <strong>da</strong>bali temperaturebisSemTxvevaSi, rodesac γ >>1.amisaTvis ganvixiloT “mcire“ siC-~qariT moZravi eleqtroni: Ρ = exp[ − Γ ( ) | | ]Acγ t exp( ) ;22⎢±i ΓAcγγ⎥⎣ mVs⎦(3.52)( α < 1; γrel>> 1; t ≥ τ Ac)(3.52)–korelaciuri funqciebis asimptoturi gamosaxulebebis gamoyva-nisasCven visargebleT (3.25) – TanafardobebiT.Aamgvarad, rogorc (3.52) –formulebi<strong>da</strong>n Cans, “siCqare – siCqareze” –korelaciuri funqciebi eqsponencialurad miilevian drois mixedviT128


<strong>da</strong>bali temperaturebis drosrel( γ >> 1), Γ ( γ ) − milevis dekrementiT. naTe-lia,rom miRebuli Sedegi napovnia Sfm-is gamoyenebis gareSe, <strong>da</strong> gan-sxvavdeba.Sedegisagan, romelic miiReba Sfm-Si eqsponencialuri Tana-mamravliT:⎡ ihγrel⎤exp ⎢± Γ ( γ ) .2 Ac ⎥ [121-122].⎣ mV s ⎦vipovoT axla eleqtrogamtaroba <strong>da</strong> <strong>da</strong>baltemperaturuli ZvradobaeleqtronisTvis erTzonian miaxloebaSi <strong>da</strong> izotropul SemTxvevaSi akustikuripolaronis modelSi susti eleqtron- fononuri bmis dros. TuvisargeblebT (3.17), (3.19) <strong>da</strong> (3.25) – formulebiT, maSin kuTri ele-qtrogatarobisaTvismiviRebT gamosaxulebas [121-122]:Ac2 relne Γ ⎡ ⎤Ac(γ)hγrelReσAc(ω)= cos⎢Γ ( γ)2 2rel2 Ac ⎥m ω +ΓAc( γ)⎣mVs⎦(3.53)( α < 1; γmV>> 1; ω > 1)(3.54)rogorc (3.54) – formulebi<strong>da</strong>n Cans, temperaturuli Sesworeba ele-qtronis<strong>da</strong>baltemperaturul, dreiful, statikur (dc)−Zvradobaze, romelicganpiribebulia sawyisi korelaciebis gaTvaliswinebiT am modelSiwarmoadgens Zalian mcire sidides:∆µAche≈2m V2s32αγe2 −4γ;( α < 1; γ >> 1)∆ µ Ac 2 2 8γ≈ 2048 ⋅αγ e− ;(3.55)µAcmiRebuli (3.54- 3.55)–formulebi warmoadgenen Tanmimdevrul <strong>da</strong> koreqtulSedegs eleqtronis <strong>da</strong>baltemperaturuli Zvradobisa akustikuri polaronismodelSi susti eleqtron – fononuri bmis SemTxvevaSi [121-122].gamovTvaloT axla eleqtrogamtaroba <strong>da</strong> dreifuli Zvradobaakustikuri polaronis modelSi eleqtruli velis maRali sixSireebis129


SemTxvevaSi, rodesac sruldeba (3.29)–Tanafardoba romelic akusti-kuripolaronis modelSi miiRebs Semdeg saxes:2~ ~ ~ 1Γ relAc( γ , Ρ)


2 1γ >> 1;( ~~ th γω) ⇒ 1. amitom (3.57) formuli<strong>da</strong>n gamomdinare (Tu CavatarebTγω 2martiv gar<strong>da</strong>qmnebsa <strong>da</strong> gamoTvlebs) dinamiuri gamtarobisTvis gveqnebaSemdegnairi (asimptoturi) yofaqceva:ω~2Re σ~0128( ω~) ≈ α3γe−4γAC ; ( >> 1, γ → ∞);α < 1γ (3.59)amrigad, am areSi eleqtrogamtaroba ukuproporciulia sixSiris kvadratisa(maRali sixSireebis SemTxvevaSi) <strong>da</strong> miileva eqsponencia-lurad Ttemperaturis SemcirebasTan erTad.II) maRal temperaturaTa are, rodesac~ΓrelAC1( γ , ~ p )


ogorc ukve aRniSnuli iyo naSromis I TavSi, eleqtronis <strong>da</strong>ba-ltemperaturuliZvradobis gamosaTvlelad akustikuri polaronis modelSisusti eleqtron-fononuri bmis SemTxvevaSi ( α < 1), gamoiyeneba kinetikuri(bolcmanis) gantolebis meTodi [99,108]. gareSe eleqtruli velis mixedviTgawrfivebuli bolcmanis gantolebis amoxsnisas relaqsaciis droismiaxloebaSi, <strong>da</strong>jaxebiT integralebSi ga<strong>da</strong>svlis sixSireebisa <strong>da</strong> TviT amintegralebis gamoTvlisas, gaiTvaliswineba mxolod `<strong>da</strong>naklisis” wevrebi.aseTi saxis miaxloebis Sesruleba (araferi rom ar vTqvaT Sfm-ze)warmoadgens sakmaod uxeSs <strong>da</strong> zoga<strong>da</strong>d arasrulyofilad asaxavseleqtronuli ga<strong>da</strong>tanis movlenebs eleqtron-fononur sistemaSi.warmodgenil modelSi, zemoT Tqmuli miaxloebebis farglebSi, eleqtronisganawilebis funqciis relaqsaciis sixSires aqvs Semdegi saxe:rel r 2π2ΓBAC(β , p)=2 ∑ Vkh kr2⎛ hkkp ⎞x δ ⎜ Vsk⎟+ + ; Γ2mm⎝⎠~ rrel ~ 8αrΓBAC(γ , p)= ∫ dKKπr2⎛ hkδ ⎜ +⎝ 2mr2( , ~ mVp )sγ =h[ Ν ( β )krelBACkpm~ΓrelBAC⎞−V k ⎟s+ (1 + N⎠r( γ , ~ p );( β ))xr2rr ~ rr2rr ~[(1+ N (4γK ) δ ( K + Kp + K ) + N (4γK)δ ( K + Kp − K )]sa<strong>da</strong>c: uganzomilebo talRuri veqtori K rformulebSi) ganisazRvreba TanafardobiT:k(3.61)(iseve rogorc (3.57) <strong>da</strong>(3.58)r h rK = ⋅ k ;2 mVsmartivad dgindeba, rom <strong>da</strong>bali temperaturebis SemTxvevaSi (γ >>1) <strong>da</strong>~`mcire~ siCqariT moZravi eleqtronisTvis ( P 2 1, α < 1).(3.62)(3.62)-is <strong>da</strong>xmarebiT ki martivad vpoulobT eleqtronis <strong>da</strong>baltemperaturulZvradobas (Sfm-Si) akustikuri polaronis modelSi:µhe1 4γ= ⋅ e ;( γ >> 1, α 1).2 2m Vs 32α0 BAC


amrigad, sadisertacio naSromSi avtoris mier miRebuli Sedegiakustikuri polaronis modelSi eleqtronis <strong>da</strong>baltemperaturuli(statikuri) dreifuli ZvradobisTvis (ix. (3.54) formula) Sfm-Si 1/2-jernaklebia eleqtronis `bolcmaniseul~ <strong>da</strong>baltemperaturul dreifulZvradobaze (ix. 3.63)). mamravli 1/2-is warmoSoba ganpirobebulia imrel relgaremoebiT, rom Γ ( γ )/ Γ0 ( γ ) = 2,AC BAC<strong>da</strong> TviT eleqtronis siCqaris (impu-lsis)relaqsaciis sixSiris (3.58)-gamosaxulebis integralqveSa wevrebi Seicaven~ r r~( K ⋅ P)/P 2_Tanamamravls, maSin rodesac (3.61) relaqsaciis sixSirisgamosaxulebis integralqveSa wevrebi aseT Tanamamravls ar Seicaven; xoloTviT am Tanamamravlis warmoSoba ganpirobebulia korelaciurifunqciebisTvis kinetikuri gantolebebis <strong>da</strong>jaxebiT integralebSieleqtronis siCqaris cvlilebis wevris arsebobiT misi gabnevisasfononebze (ix. (3.9), (3.12, (3.15) <strong>da</strong> 3.2 paragrafi)). swored am garemoebis gamomiiReba eleqtronis <strong>da</strong>baltemperaturuli Zvrado-bisTvis 2-jer naklebimniSvneloba am modelSi, romelic warmoadgens Tanamimdevrul <strong>da</strong> sworSedegs gansxvavebiT kinetikuri gantolebis gamoyenebiT miRebuliSedegisagan (`bolcmaniseuli~ midgomisagan) [121-122].rac Seexeba eleqtronis <strong>da</strong>baltemperaturul (statikur) Zvradobebsam modelSi romlebic miiRebian fxip-is Teoriisa (miaxloebisa) <strong>da</strong>balansis gantolebis meTodis (tornberg-feinmanis Teoriis) gamoyenebiT,avtoris mier Catarebuli gamokvlevebis safuZvelze napovnia am<strong>da</strong>baltemperaturuli Zvradobebis mniSvnelobebi <strong>da</strong> <strong>da</strong>dgenilia, rom isiniemTxvevian erTmaneTs:~ FXIP ~ TF 3 1 4γµAC= µAC= ⋅ e ; ( γ >> 1, α < 1)(3.64)4γ64αiseve rogorc polaronis frolixis modelSi, am modelSic3 -4γmamravlis warmoSobis Rrma mizezi (buneba) jer-jerobiT <strong>da</strong>dgenili araris.amrigad sadisertacio naSromis am Tavis (3.1_3.3) paragrafebSi avtorismier ganxilul modelebze <strong>da</strong>yrdnobiT miRebuli Sedegebi (gamoyvaniliformulebi: rogorc zogadi, aseve miaxloebiTi) SesaZleblobas iZlevaga<strong>da</strong>ugvarebel, farTozonian, erTgvarovan (polaruli) naxevargamtarebSi,ionur <strong>da</strong> kovalentur kristalebSi eleqtronuli ga<strong>da</strong>tanis meqanikuri koe-133


ficientebis (dreifuli Zvradoba, dinamiuri gamtaroba) gamoTvlisa erTizonis miaxloebaSi kvazinawilakebis (<strong>eleqtronebis</strong>) dispersiis rogorczogadi, aseve paraboluri kanonis dros, fononebis dispersiisizotropuli kanonisa <strong>da</strong> susti eleqtron-fononuri urTierTqmedebisSemTxvevaSi.3.4 polaronis <strong>da</strong>baltemperaturuli Zvradobafeinmanis ganzogadoebul modelSipolaronuli ga<strong>da</strong>tanis meqanikuri koeficientebis (dreifuli Zvradoba,eleqtrogamtaroba) gamosaTvlelad polarul naxevargamtarebsa anionur kristalebSi SemovifargloT polaronis fgm-iT, romelic aRweriliiyo naSromis I Tavis 1.3.3 paragrafSi <strong>da</strong> romlis modeluri hamiltonianiSH GF moicema (1.52)-tolobiT. polaronis dreifuli Zvradobis sapovneladvisargebloT kubos wrfivi gamoZaxilis TeoriiT <strong>da</strong> gamoTvlebisgasamartiveblad SemovifargloT 1.33 paragrafSi warmodgenil erTeulTasistemiT: ( h = m = ω 1). CavTvaloT, rom deni romelic figurirebs (3.2)-0 =formulaSi, ganpirobebulia eleqtronisa, <strong>da</strong> fiqtiuri nawilakis(polaronis) masaTa centris ga<strong>da</strong>adgilebiT, vinai<strong>da</strong>n isini <strong>da</strong>kavSirebuliarian erTmaneTTan. amgvarad, ganixileba sistema, romelic aRiwerebahamiltonianiT [57-58,125]:HsGFHGF+ H + H int=∑(3.65)sa<strong>da</strong>c: H∑-fononuri velis hamiltoniania, xolo H inturTierTqmedebishamiltoniani ganisazRvreba (1.2), (1.18) <strong>da</strong> (1.20)-tolobebiT. eleqtronfononuriurTierTqmedeba ganixileba rogorc mcire SeSfoTeba. naTelia,rom eleqtronis r -koordinati <strong>da</strong>kavSirebulia axal kanoni-kurcvladebTan TanafardobiT (ix. 1.33. paragrafi):rMGF= Rr+ µeξr; µe= , µ ≡ µe(3.66)M + 1GFSemovifargloT erTi zonis miaxloebiT <strong>da</strong> izotropuli SemTxveviT<strong>da</strong> ganvixiloT, magaliTad polaronis `impulsi-impulsze~-korelaciurifunqciis z-komponenti.134


)ΡzS Ρ)ΡsGFz( t)GF= Z−1GF( β ) S ΡGF ∑⎡⎢ e⎣− βHGFiH GF thi− H GF th)'' )GFGF−1t L GF t −βH GF[ Ρ z G z ( t,β )] ; G z ( t,β ) = Z GF ( β ) S Ρ [(e Ρ z ) e ])Ρze∑)Ρze⎤⎥⎦=(3.67)ZGF(GF−βHβ)= SΡ( e ) Pˆ ≡GF∑zsa<strong>da</strong>c: Cven SemoviReT <strong>da</strong>mxmare (relevanturi) operatori G GF ( t,β )msgavsi gamosaxuleba gveqneba agreTve korelaciuri funqciisTvis:)Ρ)z ( t) Ρ(t)GFz.. rogorc (3.67)-tolobebi<strong>da</strong>n Cans kvali korelaciuri funqciis)gamoTvlisas aiReba Ρ > n > − . orTonormirebul sakuTar funqciebzeSredingeris (1.54) <strong>da</strong> (1.55)-gantolebebisa;u n(ξ v )v) ) v)s GFGFn ≡ ); . S Ρ [ Ρ G ( t)] = ∑∫dΡΡG ( Ρ,n,t,β)<strong>da</strong>GGFzzhzzv) v)v)GF( Ρ,n,t,β ) = Ρ < n G ( t,β n Ρ(3.68)GFz z)) )martivad SesaZlebelia naCvenebi iqnas, rom korelaciuri funqcia Ρ z(t) Ρ(t)<strong>da</strong> G GF ( t,β ) -operatori akmayofileben Semdegi saxis kinetikur gantolebasz(ix. Se<strong>da</strong>rebisaTvis (3.4)-gantoleba):−t∂∂t) )⎡)∂ ⎤ i ⎧⎡ˆ)sGFss= Ρ ⎤ GFΡ⎫z Ρz( t)= S ΡGF⎢ΡzGz( t,β ) ⎥ S GF ⎨ Ρ z,H GF . Gz( t,β ) ⎬ −⎣ ∂t⎦ h ⎩⎢⎣⎥⎦ ⎭) rr rr−iτiτS ikr −ikr(τ ) GF[ e N ( β)+ e (1 + N ( β)] SP {[ P , e ] ⋅ e G ( t,β)}2∫dτ∑ V rGF Z −⋅Z+r k000sa<strong>da</strong>c:k+t−iβ∫0dz∑rkV2rkrr ) rriz−izS −ikr( z)ikr GF[ e N ( β)+ e (1 + N ( β)] ⋅ SP { e [ P , e ] ⋅G( t,β)};0r − ganisazRvreba (3.66) – tolobiT <strong>da</strong>0GFZr )rZ(3.69)siH tS(gf −iHGF tt = e rewarmoa-dgenspolaronis Tavisufali moZraobis “traeqtorias” fgm-Si. analogiurad) ) ) )Caiwereba kinetikuri gantoleba < PZ( t)PZ>GF=< PZPZ( −t)>GFkorelaciurifunqciisaTvis. Tu gaviTvaliswinebT (3.66) – tolobas, CavatarebTintegrebas τ <strong>da</strong> z - cvladebiT, maSin martivi gar<strong>da</strong>qmnebisa <strong>da</strong> gamoTvlebisSemdeg miviRebT kinetikur (moZraobis) gantolebas G GF Z(t, β )- operatorisr)diagonaluri matriculi elementebisaTvis- G GF ( P,n,t,β ) :∂G∂tGFZr)( P,n,t,β ) = iZ2 KZ∑ V r ) ×kPrk , n1,n2z135


⎧r⎡r)− ∆− ⎤− ⎡ ∆+ v r )1 exp it ( k,P,n⎤⎫⎪1n2)1 exp it ( k,P,n1n2)⎢⎣⎥⎦⎢⎣⎥⎦ ⎪× ⎨N0(β ) r r) + (1 + N0( β ))⎬ ×−+ r r )⎪ ∆ ( k , P,n1,n2)∆ ( k , P,n1,n2)⎪⎩⎭r rrr r)iµk−ikGF2 Z< | |1> ( ,2,, , ) − ∑ | |ke ξµ e ξn e n n e n GZP n n t β i Vs) ×r kk , n1 , nP2Z⎧⎡+ r rr))⎤⎫−1 − exp − i(t − iβ) ∆ ( k,P,n , )⎪ 1 − exp[ − ( − ) ∆ ( , , , )]1ni t iβk P n1n⎢⎣⎥⎦ ⎪× ⎨N0( β )r r)+ (1 + N0( β ))⎬−+ r r )P⎪∆ ( k,P,n1,n)∆ ( k,P,n1,n)⎪⎩⎭rrr rr)−iµekξiµekξGF× < n e | n >< n | e | n > G ( P,n , n,t,)aq|1 12 Z 2βr rs2 )r r) k kP∆ ± ( k,P,n1,n2)= + ± 1+εn−ε1 n22MM(3.70).−sidide warmoadgens fononebze gabnevisaspolaronis energiis cvlilebas misi erTi aRgznebuli energe-tikulimdgomareobi<strong>da</strong>n meore aRgznebul mdgomareobaSi ga<strong>da</strong>svlis dros;M ≡ MGF+1-ki polaronis masaa. Tu (3.70) – gantolebaSi Sevasru-lebT Casmasr)t → −t martivad vpoulobT gantolebas G GF ( P,n,−t,β ) sididisaTvis. cxadia,rom (3.70)- kinetikuri gantoleba ar warmoadgens bolcmanis tipisgantolebas, vinai<strong>da</strong>n am gantolebis <strong>da</strong>jaxebiTi inte-gralebi Seicavenaradiagonalur matricul elementebs G GFZ( t,β)operatorisa:r)r)r)GFGFG P,n , n,t,β ) =< P | < n | G ( t,β ) | n > | P . naTelia, rom ajamva (3.70) –Z(2 2 Z>gantolebis marjvena mxareSi xorcieldeba Sredingeris (1.54)–gantolebisyvela | n >≡ ( ξ r) −orTonormirebuli ZiriTadi <strong>da</strong> aRgznebuli (zoga<strong>da</strong>du nga<strong>da</strong>gvarebuli) mdgomareobebis mixedviT. (Cven vTvliT, rom ZiriTadimdgomareobis| 0 > −energetikuli done ε − ar aris ga<strong>da</strong>gvarebuli).r)bolcmanis tipis kinetikuri gantolebis misaRebad G GFZ( P,n,t,β )v)sididisaTvis warmovadginoTG GF ( P,n2,n,t,β)− aradiagonaluri matriculielementebi Semdegi formiT:r)r)GFGFG P,n , n,t,β)= G ( P,n,t,β)δ + exp it(εZsa<strong>da</strong>c~G GFZZ0Z~ GF[ −ε)] G ( P,n , n,t,β)1[ −δ]:( 2 Zn2nn2n Z 2n 2 nδn 2 n− warmoadgens kronekeris simbolos <strong>da</strong> SemoRebuli sidider)( P,n2,n,t,β ) −Se<strong>da</strong>rebiT mdored icvlebar)(3.71)t −didi droebis asimptoturareSi t ≥ τ ). ganvixiloT did droTa mniSvnelobebi, rodesac(rel−1t >> | ε −ε| ;( n , n = 01, ,2,...)(3.72)ninjij136


Tu CavsvamT (3.71)–tolobas (3.70)–kinetikuri gantolebis marjvena mxareSi<strong>da</strong> gaviTvaliswinebT (3.72)–utolobas, maSin miviRebT bolcmanis saxisv)kinetikur gantolebas G GF ( P,n,t,β ) −sididisaTvis. (Cven ugulvebelyaviTZ<strong>da</strong>jaxebiTi integralebi aradiagonaluri matriculi elementebiT, vinai<strong>da</strong>nisini warmoadgenen swrafad oscilirebad funqciebs didi droebisSemTxvevaSi) [125]:⎧r⎡r)− ∆− ⎤− ⎡ ∆+ r r )⎤⎫∂ v)1 exp ( , ,1,)1 exp ( , ,1GF r2 kit k P n nit k P nnZ ⎪ ⎢⎣⎥⎦⎢⎣ ⎥⎦ ⎪GZ( P,n,t,β)= i∑ | Vr | ) ⎨N0(β)r + (1 +⎬×−0()kv)N β rr∂+ )tk,n P1 Z ⎪ ∆ ( k,P,n1, n)∆ ( k,P,n1, n)⎪⎩⎭r rr r r)iµk−ikGFke ξµ e ξ2Z× < n | e | n >< n e n > ⋅GZP n t −i∑Vr)1 1| | ( , , , β)| | ×r kP⎧r⎡r)− ⎤⎡+ r r )1−exp − i(t − iβ) ∆ ( k,P,n− − − ∆ ⎤⎫⎪1,n)1 exp i(t iβ) ( k,P,n1, n)⎢⎣⎥⎦⎢⎣⎥⎦ ⎪× ⎨N0(β )r)+ (1 + N0(β ))⎬×−+ r r )⎪∆ ( k,P,n1,n)∆ ( k , P,n1,n)⎪⎩⎭rrr r r)−iµekξiµekξGF−1× < n e | n > × < n | e | n > G ( P,n,t,); t >> | ε −ε|(3.73)k,n|1 1Zβ1Zn i n j(3.73) gantolebaSi ajamva n 1− simboloTi moicavs agreTve yvela im mdgomareobebs,romelTaTvisac ε = ε , vinai<strong>da</strong>n zoga<strong>da</strong>d aRgznebulin2 n 1| n > − mdgomareobebis energetikuli speqtri ga<strong>da</strong>gvarebulia. msgavsi saxisr)v)gantolebebi gveqneba agreTve G GF ( P,n,−t,β ) <strong>da</strong> ( P,0,t,β)− ZiriTadiZmdgomareobis ε | 0 ) matriculi elementebisaTvis. Tu CavatarebT (3.73)-(0 ,>r)gantolebisa <strong>da</strong> misi msgavsi gantolebis G GF ( P,n,− t,β ) − sididisaTvisintegrebast −droiTi cvladis mixedviT, gaviTvaliswinebTG GFZ( ± t,β ) − operatorebisaTvis sawyis pirobebs t = 0 − drois momenti-saTvis:r) ) )GF−1 −βH) )GFG (0, β ) = Z GF ( β)P SP ( e ); < P P ( t)> <strong>da</strong> < PZPZ( −t)>GFkorelaciuriZZΣZZGFfunqciebisTvis (3.68) formulebs, maSin am korelaciuri funqciebisTvismiviRebT Semdegi saxis gamosaxulebebs:β 3/2( )⎡r)) )2⎤± > = MPnPZPZ( t)2πr)βε 2 βGF∑∑e∫dPP⎢ − ⎥ ×−Zexpβεne n⎢⎣2M⎥⎦


− ⎡ ∆− ⎤r) 1 cos ( , ,⎪1,)−GF2sa<strong>da</strong>c, Γ= −⎢⎣⎥⎦ −⎨[ + ]∆ ( , , 1,)Re ( , , , )kt k P n nr r)Zβ k P n nZ t β P n ) | V | N0(β )1 e∑rk , n1PZ⎧r r )rv rk2−)⎪ ∆ ( k,P⎩, n , n)r⎡r)− ∆+1 cos t ( k,P,n n ⎤1,)+ ( 1+N⎢⎣⎥⎦0(β )) r v) ×12+∆ ( k,P,n , n)11r+r)− ∆ /−[ + e ]} Pr vr rβ ( k,, n1 , n)iµki ek1< n | ee ξµ ξ| n >< n | e |1n >r v)⎧−v)⎪ sin [ ∆ ( , , ]GFkt k P nZ 21n<strong>da</strong>Im ΓZ( t,β , P,n)=∑vk , n1r⎡r)∆ ⎤r)2+∆ ( k,P,n1,n)kr ξn >(3.75))PZ| V r | ⎨N0( β )kr v2−)⎪⎩ ∆ ( k,P,n1,n)+r−r)sin t ( k,P,n1nr+r)− ∆ ( , , 1,)[ − ] + +⎢⎣⎥⎦ − ∆ ( , , 1,1 e(1 N0())[ 1−e ] Pr vβ k P n nβ k n niµekξβ r} < n | e | n1> ×× < n1| e−iµ re|+⎫⎪× ⎬⎪⎭xolo, TviT korelaciuri funqciebis milevis dekrementisaTvis(polaronisimpulsisZ − komponentis relaqsaciis sixSirisTvis) <strong>da</strong> oscilirebadifaqtorisaTvis gveqneba Semdegi Tanafardobebi:r)GFr)−1 GFRe Γz( t,β,Ρ,n)kz 2((t >> | εn i− εn j| ) ; ΓZrel( β , Ρ,n)= lim| t|→∞= −2π∑ ) | Vr| ×rk| t |rk , n Ρ1 zr r)r v)rrrr−+iµekξ−iµekξ× N β)⋅δ∆ ( k,Ρ,n , n)+ (1 + N ( β))δ ∆ ( k,Ρ,n , n)< n | e | n >< n | e | n{0( [1]0[1]} 1 1> ;r)r)GFGFβr)GFIm ΓZ ( β , Ρ,n)= lim| t|→∞Im ΓZ( t,β , Ρ,n)= ΓZrel( β , Ρ,n)Signt2napovni (3.74) formulisa <strong>da</strong> (3.2)–(3.3) Tanafardobebis <strong>da</strong>xmarebiT(3.76)martivad vRebulibT polaronisTvis eleqtrogamtarobis tenzoris disipaciurinawilis mniSvnelobas ganxilul izotropul SemTxvevaSi [125]:Re σGFSzzNe( ω)=Msa<strong>da</strong>c:× exp2212th(βω)2ω∞∫0β( )dt cos( ωt)2πMe∑)r)GFGF[ Re ΓZ( t,, Ρ,n)] cos[ ImΓZ( t,β,Ρ,n)]n3r)r) β2⎡ 2)⎤−βεΡn 2⋅− ∑e∫dΡΡZ⋅exp⎢−⎥ ×βε nn2Mβ (3.77)N −warmoadgens polaronebis koncentracias gamtarobis zonaSi.polaronis <strong>da</strong>baltemperaturuli dreifuli Zvradobis gamosa-Tvleladfgm-Si ganvixiloT kristalis Zalian <strong>da</strong>bali temperaturebis zRvruliSemTxveva, rodesac:⎢⎣⎥⎦β−1>> 1;β


sa<strong>da</strong>cε 1− warmoadgens polaronis pirveli aRgznebuli mdgomareobisenergias; (3.78) – pirobebis <strong>da</strong>cvis SemTxvevaSi ZiriTad wvlils (3.67)-(3.74)korelaciur funqciebSi (ix. agreTve (3.77)) iZlevian polaronisGF 1mdgomareobebi, romelTaTvisac: Er) ≈ β− = ⎜ ⎟ ∫ ΡΡ exp⎢−⎥⋅exp[ −Γ ( , Ρ)⋅|| ]⎡ βz ztGFdzzrelβ t ×GFr) ⎤exp⎝2πM⎠ ⎢⎣2M⎢± i Γzrel( β,Ρ)⎥(3.79)⎥⎦⎣ 2 ⎦r)GFkr r)r r)z−+ΓzrelΡ = − ∑ V r2( β , ) 2π) | | { N ( ) [ ∆ ( k,Ρ)] + (1 + N ( )) [ ∆ ( k,Ρ)]}×r k 0β δ0β δΡkzµ 2× | < 0 |r ξrr)r)i ekGF β GFe | 0 > | ; Im⋅Γz( β , Ρ)= Γzrel( β,Ρ)2r rrr)2 r) k k ⋅Ρsa<strong>da</strong>c: ∆ ± ( k,Ρ)= + ± 1.2MMr)2−1Ρ( β >> 1; β 1, β


mokidebuli TviT polaronis Ρ v )−impulsis sidideze <strong>da</strong> ganisazRvrebaSemdegi TanafardobiT:r)GFGF 2Γzrel( β , Ρ)≡ Γ0rel( β ) =3αN0( β ) M f ( 2M)r)2( β >> 1, Ρ / 2M |(3.81)N−[ e − ] 10(β ) = β 1polaronis <strong>da</strong>balsixSiruli eleqtrogamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturuliZvradobis sapovnelad fgm-Si visargebloT (3.77), (3.79) <strong>da</strong> (3.80) –formulebiT. martivi gamoTvlebis Sesrulebis Semdeg Cven vRebulobTSemdegi saxis gamosaxulebebs polaronis kuTri eleqtrogamtarobisa <strong>da</strong>ZvradobisTvis [125]:12th(βω)GFGF2 −1Γ⎡ ⎤=20rel( β)β GFRe σ ( ω)Ne β Mcos⎢Γ0( β)2 2GFrelω ω + Γ ( β)⎣ 2 ⎥(3.82)⎦0relGF−1( ω


f ( k)≡< 0 | ekr ξ 2F1( k)2 2 2 12| 0 > | ; sa<strong>da</strong>c F2(k)= B0( a)(k + 4b) ;F ( k)iµ re=28 4 2 12 610 8 28<strong>da</strong> F ( k ) = 16384b[ b B ( a)k + 2bB ( a)B ( a)k + b ( B ( a)+ 2B( a)B ( a k +1 11 221 3)106 12 2+ 2b( B ( a)B ( a)+ B ( a)B ( a))k + b ( B ( a)+ 2B( a)B ( a))k142332142 16 2+ 2b B ( a)B ( a)k + b B ( a)](3.84)34444+aq:B0( a)+ 45a2;= 14 + 42a; B1 ( a)= 1−3a;B2( a)= 36 −132a+ 90a222B ( a)= 240 −144a−1200; B a)= 448 + 1344a+ 1440a= 32B( )3a4(0axolo, a <strong>da</strong> b - sidideebi (mudmivebi) warmoadgenen variaciul parametrebsfgm-Si. ganvixiloT polaronis fgm-is zRvruli SemTxvevebi:I. Zlieri eleqtron-fononuri urTierTqmedeba:Zlieri eleqtron-fononuri bmis zRvrul SemTxvevaSi, rodesacα >> 1, M >> 1;( M → ∞,C → ∞),µ → 1GFGFtalRuri funqcia ga<strong>da</strong>dis pekaris talRur funqciaSi:2 2 −bΠξ[ 1+b ξ a b ξ ] e ;u ( ξv ') ⇒ Nα = b Π; β ≡ β = a b 2Π Π Π;0Π Π+ΠΠe(ix. 1.33 – paragrafi ) fgm-is<strong>da</strong> manormirebeli mamravli tolia:NΠ2b=π(14+ 42a3ΠΠ+ 45a2Π− sididis,)xoloaΠ<strong>da</strong>bΠ-pekaris variaciuli parametrebia, romlebic SerCeulerTeulTa sistemaSi moicemian Semdegi saxiT: b = 0,65852α; a = 0, 4516. (ix.1.3.1 paragrafi ). vinai<strong>da</strong>n f −Πfunqcia warmoadgens ori mravalwevrisSefardebas <strong>da</strong> fgm-Si <strong>da</strong> M M + 1- aris polaronis efeqturi masa,=GFΠamitom Tu SevinarCunebT wamyvan wevrsmaSin Cven miviRebT:α −s rigis mixedviT f −funqciaSi,12 2 1216384bΠB1( aΠ)kf ( 2M) ≈; k = 2M ; ( α >> 1)(3.85).2 2 12( k + 4b)Πvinai<strong>da</strong>n pekaris TeoriaSi4MΠ≈ α <strong>da</strong> = M + 1 → MΠ,MGFamitom xarisxTa12rigis gamoTvla gviCvenebs, rom: f ( 2M) ≈ α− ;( α >> 1).amrigad, <strong>da</strong>baltemperaturuliZvradobisTvis polaronis fgm-Si vRebulobT Semdegi saxisyofaqcevasα −bmis mudmivas xarisxis rigis mixedviT [125]:µ3 GF13oΠ ; ( >> 1, β >> 1)e= exp( β )2αf (M 3e≈ exp( β ) α2M) 2α (3.86)141


maSin rodesac polaronis pekaris TeoriaSi (ix. 1.3.1- paragrafi) <strong>da</strong>baltemperaturuliZvradobis yofaqceva α −bmis mudmivas xarisxis rigismixedviT moicema Semdegi <strong>da</strong>mokidebulebiT:5µ0≡ µ0Π ≈ α ;( α >> 1, β >> 1) (SevniSnavT, rom Zlieri eleqtron-fononuri bmisSemTxvevaSi ( α >>1)polaronis fgm-i ga<strong>da</strong>dis polaronis pekaris modelSi).II.susti eleqtron-fononuri urTierTqmedeba:susti eleqtron-fononuri bmis zRvrul SemTxvevaSi, rodesacMGFα < 1,MGF> 1)2α3GF(3.87)amrigad, polaronis <strong>da</strong>baltemperaturuli dreifuli ZvradobisTvisvRebulobT iseTive mniSvnelobas, rogoric napovnia polaronis frolixismodelSi.<strong>da</strong>bolos un<strong>da</strong> aRiniSnos, rom sadisertacio naSromSi avtorismier ganviTarebuli formalizmi (meTodebi) <strong>da</strong> miRebuli ganzogadoebulikvanturi kinetikuri gantolebebi korelaciuri funqciebisaTvisSesaZlebelia gamoyenebuli iqnas wrfivi eleqtronuli <strong>da</strong> polaronuliga<strong>da</strong>tanis meqanikuri koeficientebis (dreifuli Zvradoba, dinamiuri gamtaroba)gamosaTvlelad urTierTqmedebis rigis mixedviT SeSfoTebisTeoriis maRal miaxloebebSi zemoTganxiluli modelebisTvis, <strong>da</strong> myarisxeulebis fizikis ((polaruli) naxevargamtarebi, ionuri <strong>da</strong> kovalenturikristalebi <strong>da</strong> sxva). kvantur dinamiuri sistemebis sxva modelTaTvisac,romlebic urTierTqmedeben fononebTan (<strong>eleqtronebis</strong> gabnevaarapolarul optikur fononebze, piezoeleqtruli gabneva, polaronisfeinmanis modeli <strong>da</strong> sxva).142


<strong>da</strong>skvna1. sxva<strong>da</strong>sxva midgomebis-mowesrigebul operatorTa <strong>da</strong> liuvilissuperoperatoruli formalizmisa <strong>da</strong> proeqciuli operatoris meTodisgamoyenebiT, sawyisi korelaciebis gaTvaliswinebiT- gamoyvanilia axali,zusti, ganzogadoebuli kvanturi evoluciuri (kinetikuri) gantolebebidrois ormomentiani wonasworuli korelaciuri funqciebisTvis, dinamiuriqvesistemisTvis romelic urTierTqmedebs bozonur velTan (TermostatTan).miRebul gantolebaTa <strong>da</strong>jaxebiTi integralebi Seicaven rogorc wevrebs,romlebic aRweren namdvili korelaciebis evolucias droSi, aseve sawyisikorelaciebis evoluciur wevrebs, romlebic ganpirobebulia qvesistemisurTierTqmedebiT bozonur TermostatTan drois sawyis momentSi.2. SeSfoTebis Teoriis meore miaxloebaSi – qvesistemis TermostatTanurTierTqmedebis hamiltonianis mixedviT – napovnia ganzogadoebulikvanturi kinetikuri gantolebebi gamoricxuli bozonuriamplitudebiT korelaciuri funqciebisTvis, rogorc markoviseuli, isearamarkoviseuli saxiT, romlebic Seicaven cxa<strong>da</strong>d gamoyofil sawyisikorelaciebis evoluciur wevrebs.3. ganviTarebuli midgoma <strong>da</strong> formalizmi gamoyenebulia ga<strong>da</strong>ugvarebelfarTozonian, erTgvarovan naxevargamtarebsa <strong>da</strong> ionur kristalebSieleqtronuli <strong>da</strong> polaronuli gamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturulidreifuli Zvradobis wrfivi kvanturi Teoriis asagebad. ganxilul kvanturdinamiur qvesistemebis modelTaTvis, romlebic urTierTqmedeben fononurvelTan - eleqtron-fononuri sistemisTvis, frolixisa <strong>da</strong> akustikuripolaronis modelTaTvis, polaronis fgm–sTvis gamoyvanilia ganzogadoebulikvanturi evoluciuri gantolebebi wonasworuli korelaciuri funqciebisTvis– “deni-denze” (“siCqare-siCqareze”) – eleqtronisa <strong>da</strong> polaronisTvisSfm-is gamoyenebis gareSe.4. eleqtron-fononuri sistemisTvis, frolixisa <strong>da</strong> akustikuripolaronis modelTaTvis, SeSfoTebis Teoriis meore miaxloebaSi, sustieleqtron-fononuri urTierTqmedebis SemTxvevaSi <strong>da</strong> erTi zonismiaxloebaSi eleqtronisaTvis gamoyvanilia <strong>da</strong> gamokvleulia markovissaxis kinetikuri gantolebebi eleqtronis siCqaris operatoriskomponentebis saSualo mniSvnelobebis diagonaluri matriculielementebisaTvis, romlebic warmoadgenen bolcmanis tipis gantolebebs,sai<strong>da</strong>nac gamoricxulia fononuri amplitudebi. Gganxilulia eleqtronisaradrekadi gabnevis procesebi fononebze <strong>da</strong> <strong>da</strong>dgenilia, rom ganxilulmodelebSi adgili aqvs relaqsaciur process korelaciuri funqciebisoscilaciebiT. Nnapovnia eleqtronis impulsis (siCqaris) relaqsaciis six-Sireebis analizuri gamosaxulebebi kristalis <strong>da</strong>bali temperaturebis Sem-TxvevaSi. gamoTvlilia eleqtronis “siCqare-siCqareze” korelaciurifunqciebis milevis dekrementebi <strong>da</strong> oscilirebadi faqtorebi.5. gamokvleulia <strong>da</strong> <strong>da</strong>dgenilia, rom eleqtronis siCqaris (impulsis)mcire mniSvnelobebisaTvis, siCqaris relaqsaciis droebi (sixSireebi)ganxilul modelebSi ar aris <strong>da</strong>mokidebuli impulsis sidideze. mciresiCqareebiTYmoZravi <strong>eleqtronebis</strong>Tvis Zalian <strong>da</strong>bali temperaturebis drosnapovnia <strong>da</strong>balsixSiruli eleqtrogamtarobisa <strong>da</strong> eleqtronis dreifuliZvradobis gamosaTvleli formulebi.6. frolixis polaronis modelSi miRebuli gamosaxulebebi eleqtronis<strong>da</strong>baltemperaturuli dreifuli Zvradobisa <strong>da</strong> dinamiurigamtarobiTvis warmoadgens osakas mier napovni Sedegis ganzogadoebasmcire intensivobis mqone <strong>da</strong>balsixSirul gareSe eleqtrul velSi, rac143


faqtiurad SesaZlebelia ganxiluli iqnas, rogorc drudes formulakuTri eleqtrogamtarobisTvis. napovnia agreTve statikuri ( ω = 0)eleqtrogamtarobisa <strong>da</strong> <strong>da</strong>baltemperaturuli dreifuli Zvra-dobisanalizuri gamosaxulebebi, rogorc frolixis, aseve akustikuri polaronismodelebSi.7. rogorc gamoTvlebi gviCvenebs, <strong>eleqtronebis</strong> gabnevisas polaruloptikur fononebze, <strong>da</strong>baltemperaturuli dreifuli ZvradobisTvis(dcmobility; ω = 0 ) miRebuli mniSvneloba 3-jer aRemateba Zvradobis immniSvnelobas, romelic miiReba bolcmanis kinetikuri gantolebisgamoyenebiT <strong>da</strong> amoxsniT relaqsaciis drois miaxloebaSi. miRebuli Sedegi3 Kwarmoadgens – “ BΤproblemis” – nawilobriv ga<strong>da</strong>wyvetas frolixis2 hω0polaronis <strong>da</strong>baltemperaturuli Zvradobis TeoriaSi.8. <strong>eleqtronebis</strong> gabnevisas akustikur fononebze (akustikuripolaronis modeli) miRebuli <strong>da</strong>baltemperaturuli dreifuli Zvradobis( ω = 0) mniSvneloba 2-jer naklebia Zvradobis im mniSvnelobaze, romelicaseve miiReba bolcmanis kinetikuri gantolebis amoxsnisas relaqsaciisdrois miaxloebaSi.9. ganxilul modelebSi napovnia agreTve eleqtronis dreifulZvradobaze temperaturuli Sesworebebi, romlebic ganpirobebulia sawyisikorelaciebis evoluciuri wevrebis arsebobiT gamoyvanili kinetikurigantolebebis <strong>da</strong>jaxebiT integralebSi <strong>da</strong> naCvenebia, rom es Sesworebebiwarmoadgenen mcire sidideebs ganxiluli Teoriis farglebSi.10. polaronis fgm-sTvis miRebuli kvanturi kinetikuri gantolebebieleqtruli denis operatoris komponentebis (polaronis impulsis) droisormomentiani wonasworuli korelaciuri funqciebisTvis gamoyenebuliapolaronis dreifuli Zvradobisa <strong>da</strong> eleqtrogamtarobis tenzorisgamosaTvlelad. Gganxilul erTzonian izotropul SemTxvevaSi,markoviseul miaxloebaSi polaronis dinamikisTvis, napovnia miaxloebiTigamosaxulebebi korelaciuri funqciebisTvis.11. kristalis Zalian <strong>da</strong>bali temperaturebis SemTxvevaSi gamoyvaniliabolcmanis tipis kinetikuri gantoleba korelaciuri funqciisdiagonaluri matriculi elementisTvis, romelic Seesabameba polaronisZiriTad mdgomareobas. gamokvleulia polaronis aradrekadi gabnevisprocesebi fononebze. napovnia impulsis relaqsaciis sixSiris (drois)analizuri gamosaxuleba <strong>da</strong> <strong>da</strong>dgenilia, rom mcire siCqariT moZravipolaronisTvis impulsis relaqsaciis sixSire (dro) ar aris <strong>da</strong>mokidebuliimpulsis sidideze.12. kubos wrfivi reaqciis Teoriis gamoyenebiT miRebulia<strong>da</strong>balsixSiruli eleqtrogamtarobis tenzoris analizuri gamosaxulebaeleqtron-fononuri sistemisaTvis erTzonian miaxloebaSi <strong>da</strong> fononebisdispersiis zogadi (izotropuli) kanonis SemTxvevaSi. gamoTvliliapolaronis <strong>da</strong>baltemperaturuli dreifuli Zvradoba fgm-Si. am modelSinapovnia agreTve temperaturuli Sesworeba polaronis dreifulZvradobaze, romelic ganpirobebulia sawyisi korelaciebis evoluciuriwevrebis arsebobiT miRebuli kinetikuri gantolebebis <strong>da</strong>jaxebiT integralebSi,<strong>da</strong> <strong>da</strong>sabuTebulia, rom es temperaturuli Sesworeba warmoadgensmcire sidides.13. ganxilulia <strong>da</strong> gaanalizebulia polaronis <strong>da</strong>baltemperaturulidreifuli Zvradobis yofaqceva susti ( α < 1) <strong>da</strong> Zlieri (α >>1) eleqtron-144


fononuri urTierTqmedebis zRvrul SemTxvevebSi. susti eleqtronfononuriurTierTqmedebis SemTxvevaSi ( MGF→ 0) , rodesac polaronis fgmga<strong>da</strong>dis polaronis frolixis modelSi, polaronis <strong>da</strong>baltemperaturulidreifuli ZvradobisTvis (γ >>1; ω =0) vRebulobT iseTive miSvnelobas,rogoric napovnia polaronis frolixis modelSi. Zlieri eleqtronfononuriurTierTqmedebis SemTxvevaSi ( MGF→∞), rodesac polaronis fgmaRadgens polaronis pekaris naxevradklasikur Teorias, <strong>da</strong>baltemperaturulidreifuli Zvradobis yofaqceva moicema Semdegi313TanafardobiT: µGF~ e.exp(γ ) α ; (0;2γ = β >> 1;ω =0); anu polaronis<strong>da</strong>baltemperaturuli Zvradoba Zlieri eleqtron-fononuriurTierTqmedebis SemTxvevaSi ( α >> 1)izrdeba α -bmis mudmivas mecameterigis proporciulad am mudmivas didi mniSvnelobebis dros, maSinrodesac polaronis pekaris TeoriaSi <strong>da</strong>baltemperaturuli Zvradobaizrdeba misi mexuTe rigis proporciulad: µ ~ α5Π; rodesac α >>1;( h = m = ω0= 1; β >> 1 ; ω = 0).14. sadisertacio naSromSi Catarebuli gamokvlevebi gviCvenebs, romganviTarebul meTodebs, romlebic <strong>da</strong>fuZnebulia kinetikuri gantolebebismiRebaze wonasworuli korelaciuri funqciebisTvis <strong>da</strong> maT gamoTvlaze,gansxvavebiT sxva midgomebisgan, ar mivyavarT ganSladi wevrebisaganSedgenili usasrulo mwkrivebis ajamvis aucileblobasTan kvazinawilakis(eleqtronis, polaronis) urTierTqmedebis mixedviT fononebTan, kristalzemodebuli gareSe eleqtruli velis <strong>da</strong>bali ( ω → 0) sixSireebis Sem-TxvevaSi.naSromSi <strong>da</strong>sabuTebulia, rom arsebuli sawyisi korelaciebisevolucia <strong>da</strong> korelaciuri funqciebis oscilaciebi drois mixedviT,romlebic ganpirobebulia kvazinawilakis (zogad SemTxvevaSi kvanturidinamiuri qvesistemis) urTierTqmedebiT fononur (bozonur) velTan droissawyis momentSi, gavlenas ar axdenen relaqsaciur procesebze <strong>da</strong> isiniwarmoadgenen Zvradobebze temperaturuli Sesworebebis ZiriTad mizezs(wyaros) ganxilul modelebSi.145


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<strong>da</strong>narTibozonuri (fononuri) amplitudebis gamoricxva qronologiur <strong>da</strong>antiqronologiur T-namravlTa <strong>da</strong>xmarebiTganvixiloT axla ufro <strong>da</strong>wvrilebiT bozonuri (fononuri) cvladebisgamoricxvis meTodi (teqnika) qronologiur <strong>da</strong> antiqronologiur T-namravlTa <strong>da</strong>xmarebiT Cvens mier warmodgenili im klasis sistemebisaTvis,romlebic aRiwerebian (2.1), (2.2) saxis hamiltonianiT [109].fononuri cvladebis (amplitudebis) gamoricxva CavataroT HinthamiltonianisTvis, romelic warmoadgens wrfiv formas boze-amplitudebisgan.cxadia, rom komutatorebi: ⎡H% ( ξ) , H % ( τ)⎤ , ⎡H( ) , H ( )( ),H ( )γintλ ⎦ −⎣intint⎦−% %⎣⎤int,ξintλ ⎦ −⎡H% %⎣⎤int- warmoadgenen C sidideebs (ricxvebs) bozonuri (fononuri)velis mimarT.Tu gamoviyenebT magnusis formulas [6,81] <strong>da</strong> veilis igiveobas [6,82]Cven gveqneba:β β γ⎡ ⎤ ⎡1⎤ΤΣexp⎢− % Lint( ) ⎥ = exp ⎢ ⎡ % Lint ( ),% L∫dλH λint ( )2∫dγ∫dλ ⎣H γ H λ ⎤⎦ ⎥×−⎣ 0 ⎦ ⎣ 0 0⎦β⎡⎤× exp ⎢−% L∫ dλHint( λ)⎥;⎣ 0 ⎦tt ξ⎡i⎤ ⎡ 1⎤ΤΣexp⎢ % L∫ int ( ) ⎥ = exp ⎢⎡ % L2int ( ),% LadτH τint ( ) ⎤ ⎥×2∫dξ∫dτ ⎣H ξ H τ⎦−⎣h0 ⎦ ⎣ h0 0⎦t⎡ i⎤× exp ⎢−% L∫ dτHint ( τ)⎥;⎣ h0 ⎦tt ξ⎡ i⎤ ⎡ 1⎤ΤΣexp⎢− % Rint ( ) ⎥ = exp ⎢⎡ % R∫ 2int ( ),% RdτH τ int ( ) ⎤ ⎥×2∫dξ∫dτ ⎣H τ H ξ⎦−⎣ h0 ⎦ ⎣ h0 0⎦⎡ i× exp ⎢−⎣ ht∫0⎤% RdτHint ( τ ) ⎥.⎦ganvixiloT axla Semdegi gamosaxuleba:(1.1)153


βt⎡ ⎡ ⎤ ⎡ ⎤ΡΣ( ) ⎢ΤΣexp⎢− % Liint( ) ⎥⋅Τ Σexp⎢ % Lβ ∫dλHλa ∫dτHint( τ)⎥×⎢⎣⎣ 0 ⎦ ⎣h0 ⎦tβ γ⎡i⎤⎤ ⎡1⎤×ΤΣexp⎢ % Lint( ) ⎥⎥ = exp ⎢ ⎡ % Lint( ),% L∫dλH τint ( ) ⎤ ⎥×2∫dγ∫dλ⎣H γ H λ ⎦−⎣h0 ⎦⎥⎦⎣ 0 0⎦t ξt ξ⎡ 1 ⎤ ⎡ 1× exp ⎢ ⎡ % L2 int( ), % Lint ( ) ⎤ ⎥⋅ exp⎢×22∫dγ∫dτ ⎣H ξ H τ ⎦−⎣ h2∫dξ∫dτ0 0 ⎦ ⎣ h0 0× % R⎡ ( ), % Rint int ( ) ⎤⎣H τ H ξ ⎤⎦⋅I( t, β),−⎦sa<strong>da</strong>c, gansazRvris Tanaxmad, I( t,β ) funqcionalisTvis gvaqvs SemdegimniSvneloba:βt⎡ ⎤%⎡i%⎤⎢ ∫ int ⎥ ⎢ ∫ int ⎥h0 0LL( , β) ( β){ exp λ ( λ) exp τ ( τ )I t =ΡΣ− d H ⋅ d H ⋅⎣⎦ ⎣⎦t⎡ iR⎤⎪⎫⋅exp − dτH%⎢int ( τ ) ⎥⎬.⎣ h∫0 ⎦⎭⎪<strong>da</strong> bolos, Tu gamoviyenebT Tanafardobebs:β γ β β⎡1 ⎤L L 1L L⎢ dγ dλ⎡H% int( γ) , H% int ( λ) ⎤ ⎥+ dλ dγH% int( λ) , H%int ( γ ) =2∫ ∫ ⎣⎦−⎣2∫ ∫0 0 ⎦ 0 0=β∫γdγ dλH% γ , H%λ ;∫0 0LintL( ) ( )1 1ξ τ ( ),( ) ( ) ( )2 ⎡ ξ τh⎤ − τ ξ τ ξ2=t ξt t% L % L % L % L2∫d ∫d ⎣Hint Hint ⎦−2∫d ∫d Hint Hinth0 0 0 01=−2ht∫τ∫0 0LintintL( ) ( )dτ dξH% ξ H%τ1 1ξ τ ( τ ),( ξ) τ ξ ( τ ) ( ξ)2h⎡ ⎤ − 2=t ξt tR R R Rd d H% 2 intH% intd d H% 2intH%∫ ∫ ⎣⎦−∫ ∫inth0 0 0 01=−2ht∫τ0 0RintintR( ) ( )dτ dξH% τ H%ξ1 1τ ξ ( τ) , ( ξ) τ ξ ( τ) ( ξ)2h⎡ ⎤ + 2+t t t tL R L Rd d H% 2 intH% intd d H% 2intH%∫ ∫ ⎣⎦int− ∫ ∫0 0h0 01 1+ τ ξ ξ τ = τ ξ τ ξ2ht t t τR L L Rd d H% 2 intH% intd d H% 2intH%∫ ∫ ∫ ∫inth0 0 0 0( ) ( ) ( ) ( )β tβ t⎡ % L % L i % L % L∫d ∫d ⎣Hint Hint ⎦int int− ∫d ∫d H H0 0h0 0i− λ τ ( λ) , ( τ) ⎤ − λ τ ( λ) ( τ ) −2h2β tβ ti− % L % L iint int=− % L % Lint int2h∫dλ∫d τH τ H λh∫dλ∫dτH λ H τ( ) ( ) ( ) ( )0 0 0 0∫int;;;;(1.2)154


β tβ t% L % R i % L % R∫d ∫d ⎣Hint Hint ⎦int int− ∫d ∫d H H0 0h0 0iλ τ ( ),( ) ( ) ( )2 ⎡ λ τh⎤ + λ τ λ τ2+β iβ ti+ % R % L iint int= % L % Rint int2h∫dλ∫dτH τ H λh∫dλ∫dτH λ H τ( ) ( ) ( ) ( )0 0 0 0<strong>da</strong> SevasrulebT gasaSualoebas bozonuri (fononuri) velismdgomareobebis mixedviT, Cven miviRebT [109]:∑ΡΣ( β) ⎡⎣H % ( γ) H%( λ) ⎤⎦ = ⎡⎣(1 + N ( β )) e C%( s , γ ) ×L L −hω( k)( γ −λ) Lint intkkH 0k+ ( )( − ) +× % L hω k γ λ( , ) + ( ) % L( , ) % LC ( , ) ⎤kHs λ N ;0 kβ e CkH s γ C0 kHs λ0 ⎦ΡΣ( β) ⎡ %⎣H ( ξ) H%( τ ) ⎤⎦ = ∑ ⎡⎣(1 + N ( β)) e C%( s , ξ ) ×L L −iω( k )( ξ−τ)Lint intkkH 0k+× % Liω ( k)( ξ − τ )CkH( s, τ ) + ( ) % + L( , ) % LN ( , ) ⎤ ;0kβ e CkH s ξ C0 kHs τ0 ⎦− ( )( − )ΡΣ( ) ⎡ % R⎣ int( ) % R iω k τ ξint( ) ⎤⎦ = ∑ ⎡⎣(1 + ( )) % Rβ H τ H ξ Nkβ e CkH( s, τ ) ×0% ( , ) ( ) % ( , ) % ( , ) ⎤ ;+ R iω( k)( τ− ξ ) + R R× CkH s ξ + N0 k β e CkH s τ C0 kH s ξ0 ⎦kΡΣ( β) ⎡⎣H % ( τ) H%( ξ) ⎤⎦ = ⎡⎣(1 + N ( β)) e C%( s, τ ) ×L R −iω( k )( τ −ξ) Lint intkkH 0k% ( , ) ( ) % ( , ) % ( , ) ⎤ ;+ R iω( k)( τ− ξ ) + L R× CkH s ξ + N0 kβ e CkH s τ C0 kHs ξ0 ⎦ΡΣ( β) ⎡⎣H % ( λ) H%( τ ) ⎤⎦ = ⎡⎣ (1 + N ( β )) e C%( s, λ)×× C%+ LkH 0∑∑L L ω ( k)( iτ −hλ)Lint intkkH 0k( s, τ) N ( β) e C% ( s, λ) C%( s, τ ) ⎤ ;−ω( k)( iτ − hλ)+ L L+ k kH0 kH 0 ⎦∑ΡΣ( β) ⎡ ( ) ( ) ⎤ ⎡⎣H% λ H%τ⎦=⎣(1 + N ( β )) e C%( s, λ)×L R ω ( k)( iτ −hλ)Lint intkkH 0k.(1.3)+ − ( )( − ) +× % R ω k iτ hλ( , ) + ( ) % L( , ) % RC ( , ) ⎤kHs τ N .0 kβ e CkH s λ C0 kHs τ0 ⎦martivi gamoTvlebis Catarebis Semdeg advilad vipoviT( t β )exp ⎡Φ,⎤⎣ LRS , , ⎦funqcionalis saboloo gamosaxulebas [109]:β⎡t⎡ ⎤ ⎡ ⎤ΡΣ( ) ⎢ΤΣ exp⎢− % Liint( ) ⎥⋅Τ Σexp⎢% Lβ ∫dλHλa ∫dτHint( τ)⎥×⎢⎣⎣ 0 ⎦ ⎣h0 ⎦(1.4)t⎡ i ⎤⎤×Τ exp −int ( ) = exp ⎡Φ , , ( , ) ⎤; > 0, > 0Σ ⎢% R∫ dτH τ ⎥⎥⎣ t βLRS ⎦ t β⎣ h0 ⎦⎦⎥<strong>da</strong> (1.4) formuliT gamoxatuli ( t β )ganisazRvreba (2.20) gamosaxulebiT.Φ funqcionalis mniSvnelobaLRS , ,,155


disertaciis TemasTan <strong>da</strong>kavSirebiT gamoqveynebuliaSemdegi naSromebi:1. ???? ?.?., ????? ?.?. ??????????? ???????? ? ?????????? ?????? ???????? ????????? ????????????. 24-? ?????????? ????????? ?? ?????? ?????? ??????????.?????? ????????: ????? II: ??????????? ??????? ??? ?????? ????????????. ???????,8-10 ????????, 1986 ?., ???. 201-202.2. ????? ?.?., ???? ?.?. ? ?????? ???????? ????????. ?????????? ???????????: ???-???????? ???????? ?????????????? ??????. ???????, 14-17 ??? 1991 ?. ????????????????, ???. 1-140. ?????? ????????, ???. 83.3. Kotiya B.A., Los’ V.F. Exact equations for subsystem correlation functions and densitymatrix. The 18th IUPAP International Conference on Statistical Physics. Berlin, 2-8August, 1992, Programme and Abstracts. Exact and Rigorous Results, p. 133.4. Kotiya B.A., Los’ V.F. Exact equations for subsystem correlation functions and densitymatrix. Application in Polaron mobility. International Workshop “Polarons andApplications”, May 23-31, 1992, Puschino, Russia. Abstracts, p. 18.5. Kotiya B.A., Los’ V.F. Exact equations for subsystem correlation functions and densitymatrix. Application in Polaron mobility. Proceedings in Nonlinear Science. Polarons andApplications. Ed. Lakhno V.D. (John Wiley and Sons, Chichester, 1994), pp. 407-418(impaqt. <strong>da</strong>tvirTvis mqone).6. Kotiya B.A., Los’ V.F. To the theory of transport Phenomena in open systems. TheNorwegian Academy of Technological Sciences. The Lars Onsager Symposium. CoupledTransport Processes and Phase Transitions. June 2-4, 1993,Trondheim, Norwey. Abstracts,p. 89.7. Kotiya B.A., Los’ V.F. Exact Equations for Correlation Functions and Density Matrix of aSubsystem Interacting with a Heat Bath and their Application in the Polaron Mobility.European physical Society. Eps9. Trends in Physics. Firenze. Italy. September 14-17, 1993.Abstracts. Symposium 29. Statistical Machanics: Rigorous Results. ED. Systems, p. 130.8. <strong>kotia</strong> b. ga<strong>da</strong>tanis movlenebis Teoria eleqtron-fononuri sistemisaTvis.<strong>saqarTvelos</strong> <strong>teqnikuri</strong> <strong>universiteti</strong>s profesor-maswavlebelTasamecniero-<strong>teqnikuri</strong> konferencia. programa, 16-19 noemberi, Tbilisi,1993 w. I-Teoriuli fizika, gv. 32.9. <strong>kotia</strong> b., losi v. polaronis Zvradobis TeoriisTvis. <strong>saqarTvelos</strong> mecnierebaTaakademiis moambe. t. 149, #1, 1994 w., Tbilisi, fizika, gv. 61-68.10. ????? ?.?., ???? ?.?. ? ?????? ?????????????????? ??????????? ????????? ??????? ????????????? ????????. ?????????? ???????? ????. ???????? ????????????. ????? ??????????, ?. 59, ? 8, 1995 ?.: ? ???????? ??????????? ????????????????? «?????????????????? ????????? ? ????????????? ? ???????????????????????». ??????. ?????? 1995 ?., ???.133-138 (impaqt. <strong>da</strong>tvirTvis mqone).11. Kotiya B.A., Los’ V.F. Low-Temperature Electron Mobility of Acoustical Polaron. InPerspectives of Polarons. Editors: G.N. Chuev and V.D. Lakhno. Russian Academy ofSciences. World Scientific. Singapore. New Jersey. London. Hong Kong. 1996, p. 216-222(impaqt. <strong>da</strong>tvirTvis mqone).156


12. Kotiya B.A., Los’ V.F. On the theory on Transport phenomena in the Polaron’s Systems.The 19th IUPAP International Conference on Statistical Physics. Xiamen 31 July-4August, 1995. Programme and Abstracts. Transport and Relaxation, p. 42.13. Kotiya B.A., Los’ V.F. Gigilashvili T.G. On the theory of transport phenomena in.electron-phonons’systems. The 20 th IUPAP International Conference on StatisticalPhysics. Paris, UNESCO, Sorbonne. July 20-25, 1998. Book of Abstracts, Nonequlibriumsystems, p. 7.14. Kotiya B.A. On the theory of exact equations for correlation functions of the systemInteracting with a thermostat. Georgian Engineering News, 2005, ? 1, pp. 7-13.15. Kotiya B.A. On the theory of low-temperature electron mobility in the electron-phononsystem and Frohlich’s model of the Polaron. Georgian Engineering News, 2005, ? 2, pp.11-21.16. ????? ?.?. ? ???????? ????????? ???????????? ??????, ????????????????? ????????? ?????. ????? I. ????????? ????????????? ?????????? ? ?????????????????? ???????? ????????. Georgian Engineering News, 2005, ? 4, ???. 7-17.17. ????? ?.?. ? ???????? ????????? ???????????? ??????, ????????????????? ????????? ?????. ????? II. ???????????? ????????? ??? ?????????????? ???????? ??????? ?????. Georgian Engineering News, 2006, ? 1, ???. 7-17.157

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