Spin-Orbit Torque in Magnetic Bilayers - Spintronics Theory Group
Spin-Orbit Torque in Magnetic Bilayers - Spintronics Theory Group
Spin-Orbit Torque in Magnetic Bilayers - Spintronics Theory Group
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<strong>Sp<strong>in</strong></strong>-orbit <strong>Torque</strong>s <strong>in</strong> Metallic <strong>Bilayers</strong><br />
A. Manchon, X. Wang, C. Ortiz-Pauyac, S. Grytsyuk, P. Barba Gonzalez, H. Li, P.<br />
Birame Ndiaye, U. Schw<strong>in</strong>genschlogl<br />
K<strong>in</strong>g Abdullah University of Science and Technology,<br />
Physical Science and Eng., KAUST, Saudi Arabia<br />
External collaborators<br />
Rashba <strong>Torque</strong>: M. Chshiev, <strong>Sp<strong>in</strong></strong>tec, France<br />
<strong>Sp<strong>in</strong></strong> Hall effect: Kyung-J<strong>in</strong> Lee, Korea University;Hyun-woo Lee, Postech;<br />
Mark Stiles, Paul Haney, NIST<br />
Dzyalosh<strong>in</strong>skii-Moriya: Kyung-J<strong>in</strong> Lee, Korea University<br />
1
<strong>Sp<strong>in</strong></strong>tronics at KAUST<br />
<strong>Sp<strong>in</strong></strong> Transport <strong>Theory</strong> of Low Energy Consump7on Devices <br />
The <strong>Sp<strong>in</strong></strong>tronics <strong>Theory</strong> <strong>Group</strong> <br />
We are recruiOng!! <br />
Post-‐Doctoral PosiOon <br />
<strong>Theory</strong> of Polariton Lasers <br />
And also <br />
Faculty posiOons, PhDs… <br />
h9p://<strong>Sp<strong>in</strong></strong>tronics.kaust.edu.sa <br />
Collaborators <br />
S. S. P. Park<strong>in</strong>, IBM Almaden <br />
P. Bha9acharya, U. Of Michigan <br />
X. Wa<strong>in</strong>tal, CEA; U. Schw<strong>in</strong>genschlogl, KAUST <br />
M. Chshiev, SPINTEC; K.-‐J. Lee, Korea University <br />
H. Yang, NUS; M.D. SOles, NIST <br />
2
Consider Apply<strong>in</strong>g! <br />
<strong>Sp<strong>in</strong></strong>tronics at KAUST<br />
<strong>Sp<strong>in</strong></strong> Transport <strong>Theory</strong> of Low Energy Consump7on Devices <br />
3
1 st International Workshop on <strong>Sp<strong>in</strong></strong>-<strong>Orbit</strong><br />
<strong>Torque</strong> at KAUST (Feb. 2013)<br />
Before… <br />
AXer… <br />
4
1 st International Workshop on <strong>Sp<strong>in</strong></strong>-<strong>Orbit</strong><br />
<strong>Torque</strong> at KAUST (Feb. 2013)<br />
Before… <br />
Listen to experimentalists! <br />
The controversy <strong>Sp<strong>in</strong></strong> Hall versus Rashba effect is mean<strong>in</strong>gless (be.er <strong>in</strong>terface v.s. bulk) <br />
<strong>Sp<strong>in</strong></strong> Hall AND Rashba probably present (even more complex) <br />
Band AXer… structure is sCll to be idenCfied (experiments v.s. theory) <br />
Dyakonov-‐Perel and Dzyalosh<strong>in</strong>skii-‐Moriya play an important role (which one?) <br />
5
Outl<strong>in</strong>e<br />
I. <strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> Coupl<strong>in</strong>g Strikes Back <br />
AMR, AHE, SHE, Anisotropy, sp<strong>in</strong> relaxa;on…and <strong>Torque</strong>s <br />
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
<strong>Sp<strong>in</strong></strong> Hall <strong>Torque</strong>, <strong>Sp<strong>in</strong></strong> Hall AMR & AHE, <strong>Sp<strong>in</strong></strong> Swapp<strong>in</strong>g? <br />
III. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
Rashba torque, Dyakonov-‐Perel, Dzyalsh<strong>in</strong>skii-‐Moriya and more <br />
IV. Dzyalosh<strong>in</strong>skii-‐Moriya InteracOon <br />
From Rashba to Dzyalosh<strong>in</strong>skii-‐Moriya to doma<strong>in</strong> wall mo;on <br />
V. <strong>Sp<strong>in</strong></strong>-‐orbitronics with Magnons: The Magnonic DM <strong>Torque</strong> <br />
Marry<strong>in</strong>g sp<strong>in</strong>-‐orbitronics with sp<strong>in</strong> caloritronics <br />
6
Outl<strong>in</strong>e<br />
I. <strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> Coupl<strong>in</strong>g Strikes Back <br />
AMR, AHE, SHE, Anisotropy, sp<strong>in</strong> relaxa;on…and <strong>Torque</strong>s <br />
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
<strong>Sp<strong>in</strong></strong> Hall <strong>Torque</strong>, <strong>Sp<strong>in</strong></strong> Hall AMR & AHE, <strong>Sp<strong>in</strong></strong> Swapp<strong>in</strong>g? <br />
III. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
Rashba torque, Dyakonov-‐Perel, Dzyalsh<strong>in</strong>skii-‐Moriya and more <br />
IV. Dzyalosh<strong>in</strong>skii-‐Moriya InteracOon <br />
From Rashba to Dzyalosh<strong>in</strong>skii-‐Moriya to doma<strong>in</strong> wall mo;on <br />
V. <strong>Sp<strong>in</strong></strong>-‐orbitronics with Magnons: The Magnonic DM <strong>Torque</strong> <br />
Marry<strong>in</strong>g sp<strong>in</strong>-‐orbitronics with sp<strong>in</strong> caloritronics <br />
7
I. <strong>Sp<strong>in</strong></strong>-‐orbit Coupl<strong>in</strong>g Strikes Back <br />
a. “The Usual Old Story” <br />
8
I. <strong>Sp<strong>in</strong></strong>-‐orbit Coupl<strong>in</strong>g Strikes Back <br />
a. “The Usual Old Story” <br />
<strong>Sp<strong>in</strong></strong>-‐orbit coupl<strong>in</strong>g <strong>in</strong> solids <br />
⇒ EffecCve k-‐dependent magneCc field <br />
Transfer of angular momentum & coupl<strong>in</strong>g to the labce <br />
<strong>Sp<strong>in</strong></strong> relaxaOon <br />
Ellio.-‐Yafet <br />
Dyakonov-‐Perel <br />
Damp<strong>in</strong>g <br />
Magnon-‐magnon <br />
Magnon-‐phonon <br />
MagneOc Anisotropy <br />
Uniaxial, Biaxial etc. <br />
Dzyalosh<strong>in</strong>skii-‐Moriya <br />
Anomalous Transport <br />
Anomalous Hall effect <br />
Anisotropic Magnetoresistance <br />
Banerjee, Nano Le.ers 2011 Krivorotov, Science 2005 <br />
McGuire, IEEE Trans. Mag 1975 <br />
9
I. <strong>Sp<strong>in</strong></strong>-‐orbit Coupl<strong>in</strong>g Strikes Back <br />
b. A new hope… <br />
J. Slonczewski <br />
L. Berger <br />
J. C. Slonczewski, J. Magn. Magn. Mater. 159, L1 (1996). <br />
L. Berger, Phys. Rev. B 54, 9353 (1996). <br />
AlOx, MgO, TaN <br />
Transfer of the sp<strong>in</strong> angular momentum <br />
Need a polarizer and a free layer <br />
J. Hayakawa, JJAP 44, L1267 (2005) <br />
Co, NiFe, CoFeB <br />
Pt, Ta, Bi , W <br />
Possible Strategies <br />
<strong>Sp<strong>in</strong></strong> Hall effect <strong>in</strong> the Heavy Metal: sp<strong>in</strong> current <strong>in</strong>jecOon <br />
Miron et al., Nature Materials 2010, 2011, <br />
Pi et al., APL 2010; Suzuki et al., APL 2011 <br />
Liu et al, PRL 2011, PRL 2012, Science 2012 <br />
Kim et al., Nature Materials 2012 <br />
<br />
J z s ∝ y ⇒ T = J z<br />
s<br />
Miron Nature 2011 Liu et al., PRL 2011 Liu Science 2012 <br />
∝ m × ( y × m<br />
)<br />
HM /F<br />
Rashba effect at the Heavy Metal/Ferromagnet <strong>in</strong>terface: sp<strong>in</strong> density generaOon <br />
<br />
S ∝ y ⇒ T = Δm × S ∝ y × m<br />
<br />
z <br />
y <br />
x <br />
10
I. <strong>Sp<strong>in</strong></strong>-‐orbit Coupl<strong>in</strong>g Strikes Back <br />
b. A new hope… <br />
S<strong>in</strong>gle Doma<strong>in</strong> Measurements <br />
Methods: GHz sp<strong>in</strong>-‐FMR, kHz modulaOon <br />
Removes effects that depends on texture <br />
Doma<strong>in</strong> Wall Measurements <br />
Methods: Current-‐<strong>in</strong>duced MoOon <br />
Averages the (SO, STT, Damp<strong>in</strong>g) torques <br />
Anatomy of <strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> <strong>Torque</strong>s <br />
ˆT = T ⊥<br />
( θ) ˆm × ŷ +T || ( θ) ˆm × ( ŷ × ˆm )<br />
Miron, Nature Materials 2010, Nature 2011 <br />
Pi, APL 2010; Suzuki, APL 2011 <br />
Liu PRL 2011, PRL 2012, Science 2012; Fan Nat. Com. 2013 <br />
Kim, Nature Materials 2012, Garello Nature Nano 2013 <br />
New effects <br />
Reversed moCon (aga<strong>in</strong>st electron flow) <br />
Doma<strong>in</strong> wall distorCon and ClCng <br />
Complex Current dependence <br />
Miron, Nature Materials 2011 <br />
Emori, Nature Materials 2013 <br />
Ryu, Nature Nanotechnology 2013 <br />
Haazen, Nature Materials 2013 <br />
11
I. <strong>Sp<strong>in</strong></strong>-‐orbit Coupl<strong>in</strong>g Strikes Back <br />
b. A new hope… <br />
ˆT = T ⊥<br />
( θ) ˆm × ŷ +T || ( θ) ˆm × ( ŷ × ˆm )<br />
<strong>Sp<strong>in</strong></strong> Hall does NOT fully expla<strong>in</strong> the data <br />
Rashba is NOT sufficient either <br />
12
I. <strong>Sp<strong>in</strong></strong>-‐orbit Coupl<strong>in</strong>g Strikes Back <br />
b. A new hope… <br />
AlOx, MgO, TaN <br />
Co, NiFe, CoFeB <br />
Pt, Ta, Bi , W <br />
Bulk NM <br />
<strong>Sp<strong>in</strong></strong> Hall <br />
effect <br />
SHE <strong>Torque</strong> <br />
IOnerant sp<strong>in</strong>s <br />
SHE <strong>in</strong>duced AMR, AHE <br />
Band structure versus disorder? <br />
Rashba <strong>Torque</strong> <br />
Dy’akonov-‐Perel RelaxaOon <br />
Interface <br />
NM/F <br />
“Rashba” <br />
SOC <br />
local sp<strong>in</strong>s <br />
Dzyalosh<strong>in</strong>skii-‐Moriya <br />
Anisotropic Damp<strong>in</strong>g <br />
13
Outl<strong>in</strong>e<br />
I. <strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> Coupl<strong>in</strong>g Strikes Back <br />
AMR, AHE, SHE, Anisotropy, sp<strong>in</strong> relaxa;on…and <strong>Torque</strong>s <br />
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
<strong>Sp<strong>in</strong></strong> Hall <strong>Torque</strong>, <strong>Sp<strong>in</strong></strong> Hall AMR & AHE, <strong>Sp<strong>in</strong></strong> Swapp<strong>in</strong>g? <br />
III. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
Rashba torque, Dyakonov-‐Perel, Dzyalsh<strong>in</strong>skii-‐Moriya and more <br />
IV. Dzyalosh<strong>in</strong>skii-‐Moriya InteracOon <br />
From Rashba to Dzyalosh<strong>in</strong>skii-‐Moriya to doma<strong>in</strong> wall mo;on <br />
V. <strong>Sp<strong>in</strong></strong>-‐orbitronics with Magnons: The Magnonic DM <strong>Torque</strong> <br />
Marry<strong>in</strong>g sp<strong>in</strong>-‐orbitronics with sp<strong>in</strong> caloritronics <br />
14
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
a. DriX-‐diffusion model <br />
F: bulk AHE, bulk AMR <br />
P. Gonzales Barba <br />
NM: bulk SHE <br />
Shchelushk<strong>in</strong> and Brataas, PRB (2005) <br />
<strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> <strong>Torque</strong> <br />
AMR & AHE <br />
A. Vedyayev et al., arxiv.1108.2589 (2011) <br />
A. Manchon, arxiv (2012); Haney PRB (2013) <br />
15
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
a. DriX-‐diffusion model <br />
P. Gonzales Barba <br />
Nice comparison with Kobs et al. PRL 2011 <br />
See also Nakayama Phys. Rev. Le.. 110, 206601 <br />
16
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
b. Boltzmann Approach <br />
CollaboraCon: M.D SCles, P. Haney (NIST); K.J. Lee (Korea U.); H.W. Lee (Postech) <br />
Account for the actual sca.er<strong>in</strong>g <strong>in</strong> the layers: f<strong>in</strong>ite size effect <br />
Kim Nature Materials 2013 <br />
Haney, KJ Lee, HW Lee, Manchon & SCles PRB 87, 174411 (2013) <br />
17
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
c. Beyond <strong>Sp<strong>in</strong></strong> Hall effect: <strong>Sp<strong>in</strong></strong> Swapp<strong>in</strong>g? <br />
First order <strong>in</strong> SOC, second order <strong>in</strong> V <br />
è Captured by 1 Born ApproximaCon <br />
Fan Nature CommunicaCon 2013 <br />
Field-‐effect that does NOT <br />
come from the <strong>in</strong>terface <br />
Shchelushk<strong>in</strong> and Brataas, PRB (2005) <br />
18
Outl<strong>in</strong>e<br />
I. <strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> Coupl<strong>in</strong>g Strikes Back <br />
AMR, AHE, SHE, Anisotropy, sp<strong>in</strong> relaxa;on…and <strong>Torque</strong>s <br />
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
<strong>Sp<strong>in</strong></strong> Hall <strong>Torque</strong>, <strong>Sp<strong>in</strong></strong> Hall AMR & AHE, <strong>Sp<strong>in</strong></strong> Swapp<strong>in</strong>g? <br />
III. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
Rashba torque, Dyakonov-‐Perel, Dzyalsh<strong>in</strong>skii-‐Moriya and more <br />
IV. Dzyalosh<strong>in</strong>skii-‐Moriya InteracOon <br />
From Rashba to Dzyalosh<strong>in</strong>skii-‐Moriya to doma<strong>in</strong> wall mo;on <br />
V. <strong>Sp<strong>in</strong></strong>-‐orbitronics with Magnons: The Magnonic DM <strong>Torque</strong> <br />
Marry<strong>in</strong>g sp<strong>in</strong>-‐orbitronics with sp<strong>in</strong> caloritronics <br />
19
Metallic surfaces <br />
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
a. Interfacial Band Structure <br />
Au surface Gd/GdO <strong>in</strong>terface <br />
Bi surface <br />
E. Rashba <br />
LaShell PRL 1996 <br />
Kupr<strong>in</strong> PRB 2005 <br />
Ast PRL 2007 <br />
Huge Rashba splibng at heavy metal surface!! <br />
What happens at heavy metal/ferromagnet <strong>in</strong>terfaces? <br />
20
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
a. Interfacial Band Structure <br />
CollaboraCon: U. Schw<strong>in</strong>genschlogl; S. Grytsyuk (KAUST) <br />
Noble Metal/Ferromagnet <br />
S. Grytsyuk <br />
M=-‐M x x <br />
M=+M x x <br />
k y <br />
( σ )⋅ ˆk<br />
Ĥ = ε ( ˆk ) ⇒ Ĥ ≈ ε ( ˆk ) +α R ẑ × ˆ<br />
See Park, Kim, Lee & Han, Phys. Rev. B 87, 041301(R) 2013 <br />
21
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
a. Interfacial Band Structure <br />
CollaboraCon: U. Schw<strong>in</strong>genschlogl; S. Grytsyuk (KAUST) <br />
Noble Metal/Ferromagnet <br />
S. Grytsyuk <br />
M=-‐M x x <br />
M=+M x x <br />
k y <br />
( σ )⋅ ˆk<br />
Ĥ = ε ( ˆk ) ⇒ Ĥ ≈ ε ( ˆk ) +α R ẑ × ˆ<br />
See Park, Kim, Lee & Han, Phys. Rev. B 87, 041301(R) 2013 <br />
22
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
c. Diffusive Model for Rashba <strong>Torque</strong> <br />
X. Wang C. OrCz Pauyac <br />
3 Major Consequences <br />
Inverse sp<strong>in</strong> Galvanic effect <br />
(Edelste<strong>in</strong>) <br />
<strong>Sp<strong>in</strong></strong> Galvanic effect <br />
(see S<strong>in</strong>ova PRL 2004) <br />
Anisotropic <strong>Sp<strong>in</strong></strong> RelaxaOon <br />
(Dyakonov-‐Perel) <br />
<strong>Sp<strong>in</strong></strong> density is generated <br />
by the flow<strong>in</strong>g current <br />
Produces a sp<strong>in</strong> torque <br />
Non-‐equilibrium sp<strong>in</strong> density <br />
generates a charge current <br />
Impacts the AMR+AHE <br />
Induces anisotropic Damp<strong>in</strong>g <br />
Induces angular dependence <br />
Manchon and Zhang, Phys. Rev. B 78, 212405 (2008); 79, 094422 (2009) <br />
X. Wang and A. Manchon, Phys. Rev. Le.. 108, 117201 (2012). <br />
M. Dyakonov <br />
I. Perel <br />
23
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
c. Diffusive Model for Rashba <strong>Torque</strong> <br />
Strong Rashba sp<strong>in</strong>-‐orbit coupl<strong>in</strong>g: Dyakonov-‐Perel relaxaOon <br />
X. Wang C. OrCz Pauyac <br />
Intermediate Rashba sp<strong>in</strong>-‐orbit coupl<strong>in</strong>g (Δ=αk): Fermi surface breath<strong>in</strong>g <br />
E ±<br />
= 2 k 2<br />
2m ±<br />
2<br />
" Δ %<br />
$ '<br />
# 2 &<br />
C. OrCz, X. Wang, M. Chshiev, Manchon, APL 2013 <br />
+α 2 R<br />
k 2 + Δα R<br />
k s<strong>in</strong>θ s<strong>in</strong>( ϕ −ϕ k )<br />
24
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
d. Anisotropic Damp<strong>in</strong>g <br />
Kambersky PRB 2007 <br />
α(θ 1 ) <br />
α(θ 2 ) <br />
See also Hankiewicz PRB 2007 <br />
Other source of anisotropic damp<strong>in</strong>g: Kim PRL 108, 217202 (2012) <br />
25
Summary on <strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> <strong>Torque</strong>s <br />
<strong>Sp<strong>in</strong></strong> Hall effect <br />
Rashba effect <br />
<strong>Torque</strong>s <br />
Non-‐adiabaCc SHE Direct SHE <br />
Edelste<strong>in</strong> effect (ISGE) Intr<strong>in</strong>sic+non-‐adiabaCc <br />
D’yakonov-‐Perel anisotropic sp<strong>in</strong> relaxaCon <strong>in</strong>troduces angular dependence <br />
Transport <br />
Both contribute to anisotropic AMR+ AHE <br />
Next… <br />
<strong>Sp<strong>in</strong></strong>-‐pump<strong>in</strong>g+SHE: anisotropic damp<strong>in</strong>g? <br />
<strong>Sp<strong>in</strong></strong> Swapp<strong>in</strong>g? <br />
Anisotropic Damp<strong>in</strong>g <br />
α ≈ α 0<br />
+δα s<strong>in</strong> 2 θ<br />
Dzyalosh<strong>in</strong>skii-‐Moriya <strong>in</strong>teracOon <br />
Rashba <strong>Torque</strong> <strong>in</strong> Doma<strong>in</strong> wall <br />
26
Outl<strong>in</strong>e<br />
I. <strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> Coupl<strong>in</strong>g Strikes Back <br />
AMR, AHE, SHE, Anisotropy, sp<strong>in</strong> relaxa;on…and <strong>Torque</strong>s <br />
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
<strong>Sp<strong>in</strong></strong> Hall <strong>Torque</strong>, <strong>Sp<strong>in</strong></strong> Hall AMR & AHE, <strong>Sp<strong>in</strong></strong> Swapp<strong>in</strong>g? <br />
III. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
Rashba torque, Dyakonov-‐Perel, Dzyalsh<strong>in</strong>skii-‐Moriya and more <br />
IV. Dzyalosh<strong>in</strong>skii-‐Moriya InteracOon <br />
From Rashba to Dzyalosh<strong>in</strong>skii-‐Moriya to doma<strong>in</strong> wall mo;on <br />
V. <strong>Sp<strong>in</strong></strong>-‐orbitronics with Magnons: The Magnonic DM <strong>Torque</strong> <br />
Marry<strong>in</strong>g sp<strong>in</strong>-‐orbitronics with sp<strong>in</strong> caloritronics <br />
27
V. Dzyalosh<strong>in</strong>skii-‐Moriya <strong>in</strong>teracOon <br />
a. A short <strong>in</strong>troducOon <br />
I. Dzyalosh<strong>in</strong>skii <br />
Interfacial <strong>Sp<strong>in</strong></strong>-‐orbit coupl<strong>in</strong>g: Dzyalosh<strong>in</strong>skii-‐Moriya <strong>in</strong>teracOon <br />
T. Moriya <br />
Heisenberg exchange <br />
(0 th order <strong>in</strong> soc) <br />
I. E. Dzyalosh<strong>in</strong>skii, JETP 5, 1259 (1957) <br />
T. Moriya, Phys. Rev. 120, 91 (1960). <br />
DM <strong>in</strong>teracCon <br />
(1 st order <strong>in</strong> soc) MC Anisotropy <br />
(2 nd order <strong>in</strong> soc) <br />
Fe/Ir <br />
Mn/W <br />
Mentzel PRL (2012) <br />
Bode et al. Nature 447 (2007) <br />
28
V. Dzyalosh<strong>in</strong>skii-‐Moriya <strong>in</strong>teracOon <br />
a. A short <strong>in</strong>troducOon <br />
Dispersion of a Neel sp<strong>in</strong> spiral on Co/Ir <br />
FLEUR+non-‐coll<strong>in</strong>ear magneCsm+SOC <br />
Ferriani et al., PRL 101, 027201 (2008) <br />
M. Heide et al, PRB 78, 140403R (2008) <br />
F. Schubert et al. PRB 83, 165442 (2011) <br />
A. Belabbes <br />
Nature of the Noble Metal/F <strong>in</strong>terface <br />
29
V. Dzyalosh<strong>in</strong>skii-‐Moriya <strong>in</strong>teracOon <br />
b. Reversed doma<strong>in</strong> wall moOon <br />
DM <strong>in</strong>teracCon distort the Bloch wall <strong>in</strong>to a Neel wall <br />
Chen PRL 110, 177204 (2013) <br />
Emori, Nature Materials 2013 <br />
Ryu, Nature Nanotechnology 2013 <br />
Haazen, Nature Materials 2013 <br />
Thiaville et.al., Europhys. Le.. 100, 57002 (2012). <br />
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Outl<strong>in</strong>e<br />
I. <strong>Sp<strong>in</strong></strong>-‐<strong>Orbit</strong> Coupl<strong>in</strong>g Strikes Back <br />
AMR, AHE, SHE, Anisotropy, sp<strong>in</strong> relaxa;on…and <strong>Torque</strong>s <br />
II. What the sp<strong>in</strong> is go<strong>in</strong>g on ? <strong>Sp<strong>in</strong></strong> Hall <br />
<strong>Sp<strong>in</strong></strong> Hall <strong>Torque</strong>, <strong>Sp<strong>in</strong></strong> Hall AMR & AHE, <strong>Sp<strong>in</strong></strong> Swapp<strong>in</strong>g? <br />
III. What the sp<strong>in</strong> is go<strong>in</strong>g on ? Rashba <br />
Rashba torque, Dyakonov-‐Perel, Dzyalsh<strong>in</strong>skii-‐Moriya and more <br />
IV. Dzyalosh<strong>in</strong>skii-‐Moriya InteracOon <br />
From Rashba to Dzyalosh<strong>in</strong>skii-‐Moriya to doma<strong>in</strong> wall mo;on <br />
V. <strong>Sp<strong>in</strong></strong>-‐orbitronics with Magnons: The Magnonic DM <strong>Torque</strong> <br />
Marry<strong>in</strong>g sp<strong>in</strong>-‐orbitronics with sp<strong>in</strong> caloritronics <br />
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V. <strong>Sp<strong>in</strong></strong>-‐orbitronics with Magnons <br />
The Magnonic DM <strong>Torque</strong> <br />
CollaboraCon: K.J. Lee, J.H. Moon (Korea U.); H.W. Lee (Postech) <br />
P. Birame Ndiaye <br />
Rashba Hamiltonian for electrons <br />
Dzyalosh<strong>in</strong>skii-‐Moriya Hamiltonian for magnons <br />
Therefore, one expects a DM torque mediated by the magnons <br />
èSame direcCon as the Rashba torque: z x j <br />
Birame Ndiaye, Jung-‐Hwan Moon , K.-‐J. Lee, and A. Manchon, unpublished (2013) <br />
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V. <strong>Sp<strong>in</strong></strong>-‐orbitronics with Magnons <br />
The Magnonic DM <strong>Torque</strong> <br />
CollaboraCon: K.J. Lee, J.H. Moon (Korea U.); H.W. Lee (Postech) <br />
M<br />
(+k)<br />
(−k)<br />
H = H 0 s<strong>in</strong>(2πf 0 t)y<br />
P. Birame Ndiaye <br />
Standard RF-‐sp<strong>in</strong> waves <br />
Thermally-‐<strong>in</strong>duced magnons <br />
The magneCzaCon is Clted when <strong>in</strong>jecCng magnons <strong>in</strong> the system <br />
Birame Ndiaye, Jung-‐Hwan Moon , K.-‐J. Lee, and A. Manchon, unpublished (2013) <br />
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<strong>Sp<strong>in</strong></strong>-‐orbitronics is not messy… <br />
just a li9le bit complex <br />
<strong>Sp<strong>in</strong></strong>-‐waves (q>0) <br />
Magnons Transport <br />
Magnon Hall effect <br />
Topological magnonic crystal <br />
Damp<strong>in</strong>g <br />
Magnon-‐magnon <br />
Magnon-‐phonon <br />
<strong>Sp<strong>in</strong></strong> caloritronics <br />
Magnonic <strong>Torque</strong> <br />
<strong>Sp<strong>in</strong></strong>-‐orbit torque <br />
Extr<strong>in</strong>sic v.s. Intr<strong>in</strong>sic <br />
Bulk v.s. <strong>in</strong>terfacial… <br />
RelaxaOon <br />
<strong>Sp<strong>in</strong></strong> relaxaOon Ellio.-‐Yafet <br />
Dyakonov-‐Perel <br />
MagneOc Anisotropy <br />
Uniaxial, Biaxial etc. <br />
Dzyalosh<strong>in</strong>skii-‐Moriya <br />
Damp<strong>in</strong>g <br />
Breath<strong>in</strong>g Fermi <br />
Surface… <br />
Anomalous Transport <br />
Anomalous & <strong>Sp<strong>in</strong></strong> Hall effect <br />
Anisotropic Magnetoresistance <br />
Quantum <strong>Sp<strong>in</strong></strong> Hall effect <br />
Topological Insulators <br />
Skyrmion <br />
Chiral magnets <br />
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Thank you for your a9enOon! <br />
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