nanoelectronics - Institut d'Études Scientifiques de Cargèse (IESC)

More documents

Recommendations

Info

$flow abd transport in porous and fractured media:development ...$

Wednesday Wednesday, October 24 Thermoelectric properties of strongly correlated quantum systems Antoine Georges Collège de France, Paris - Ecole Polytechnique, Palaiseau, France - Université de Genève, Suisse Materials with strong electronic correlations, especially transition-metal oxides, have received increasing attention as possible thermoelectrics. An interesting regime is that of intermediate to high temperatures, where enough entropy is unquenched. I will describe here the theoretical understanding of the temperature–dependence of the Seebeck coefficient for simple models of interacting electrons, as well as selected experimental results. On another note, I will present a recent proposal for studying fundamental aspects of thermoelectric effects using ultra-cold atomic gases. __________________________________________________________________________ Thermopower and thermoelectric efficiency in systems with broken time-reversal symmetry Giuliano Benenti Center for Nonlinear and Complex Systems, Università degli Studi dell'Insubria, Via Valleggio 11, 22100 Como, Italy We show that in systems with broken time-reversal symmetry the maximum efficiency and the efficiency at maximum power are both determined by two parameters: a ``figure of merit'' which generalizes the thermoelectric figure of merit ZT, and an asymmetry parameter, which becomes relevant when the thermopower is not an even function of the magnetic field. In contrast to the time-symmetric case, the figure of merit is bounded from above; nevertheless the Carnot efficiency can be reached at lower and lower values of the figure of merit as the asymmetry parameter increases. Moreover, the Curzon-Ahlborn limit for efficiency at maximum power can be overcome within linear response. We show that a weak magnetic field generally improves either the efficiency of thermoelectric power generation or of refrigeration, the efficiencies of the two processes being no longer equal when a magnetic field is added. Finally, we discuss the thermopower asymmetry and thermoelectric efficiency for a three-dot ring pierced by an Aharonov-Bohm flux, for random matrix models, and for more abstract transmission models. [1] K. Saito, G. Benenti and G. Casati, A microscopic mechanism for increasing thermoelectric efficiency, Chem. Phys. 375, 508 (2010) [2] G. Benenti and G. Casati, Increasing thermoelectric efficiency: dynamical models unveil microscopic mechanisms, Phil. Trans. R. Soc. A 369, 466 (2011) [3] G. Benenti, K. Saito and G. Casati, Thermodynamic bounds on efficiency for systems with broken time-reversal symmetry, Phys. Rev. Lett. 106, 230602 (2011)
Wednesday [4] K. Saito, G. Benenti, G. Casati and T. Prosen, Thermopower with broken time-reversal symmetry, Phys. Rev. B 84, 201306(R) (2011) [5] V. Balachandran, R. Bosisio and G. Benenti, Validity of Wiedemann Franz law in small molecular wires, Phys. Rev. B 86, 035433 (2012) [6] M. Horvat, T. Prosen, G. Benenti and G. Casati, Railway switch transport model, preprint arXiv:1207.6014v1 [cond-mat.mes-hall] Heat and Nanotechnologies : Focus on Thermoelectricity Sebastian Volz Laboratoire d'Energétique Moléculaire et Macroscopique, UPR CNRS 288 ,Ecole Centrale Paris Nanotechnologies were supposed to give birth to a new revolution based on the design of new molecular nanorobot but finally consisted in the fabrication of new materials including nanostructures with enhanced properties. Thermoelectric materials are one of the outcomes and will be addressed in the talk. An introduction on nanotechnologies at broad and on nanoscale heat transport applications will be provided. Then a focus on thermoelectric materials will include a presentation of the electrical physical effects as well as the main thermoelectric applications. Heat conduction effects at nanoscales will then be presented and detailed for several key nanostructures (nanowires, superlattices and nanoparticles). The corresponding achievements in terms of figure of merit will finally be presented.
Page 1 and 2: 2012 22 Octobre 27 Octobre WORKSHOP
Page 3 and 4: Afternoon Morning Timetable Monday
Page 5 and 6: 15h50 - 16h20 Coffee Break 16h20 -
Page 7 and 8: Monday Abstracts Monday, October 22
Page 9 and 10: Monday Single-Electron Tunneling an
Page 11 and 12: Tuesday Tuesday, October 23 Random-
Page 13 and 14: Tuesday the energy level spacings a
Page 15: Tuesday Electron refrigeration by n
Page 19 and 20: Thursday [3] B. A. Bernevig, T. L.
Page 21 and 22: Thursday Electronic standing waves
Page 23 and 24: Friday Nanoscale inhomogeneities in
Page 25 and 26: Friday Electron focusing in graphem
Page 27 and 28: Friday molecules. We explain the or
Page 29 and 30: Posters Posters Ab-initio study of
Page 31 and 32: Posters Nonclassical photon-pair pr

nanoelectronics - Institut d'Études Scientifiques de Cargèse (IESC)

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?