Most of the modern spintronics developments rely on the manipulation of magnetization states via electric currents, which started with the discovery of spin transfer torque effects 20 years ago. By now, it has been realized that spin-orbit coupling provides a particularly efficient pathway for generating spin torques from charge currents. At the same time, spin-orbit effects can be enhanced at interfaces, which opens up novel device concepts. Here, we discuss two examples of such interfacial spin-orbit torques, namely, systems with inherently two-dimensional materials and metallic bilayers with strong Rashba spin-orbit coupling at their interfaces. We show how ferromagnetic resonance excited by spin-orbit torques can provide information about the underlying mechanisms. In addition, this article provides a brief overview of recent developments with respect to interfacial spin-orbit torques and an outlook of still open questions.

1.
A.
Hoffmann
and
S. D.
Bader
, “
Opportunities at the frontier of spintronics
,”
Phys. Rev. Appl.
4
,
047001
(
2015
).
2.
M. B.
Jungfleisch
,
W.
Zhang
,
W.
Jiang
, and
A.
Hoffmann
, “
New pathways towards efficient metallic spin hall spintronics
,”
SPIN
5
,
1530005
(
2015
).
3.
L.
Liu
,
C.-F.
Pai
,
Y.
Li
,
H. W.
Tseng
,
D. C.
Ralph
, and
R. A.
Buhrman
, “
Spin torque switching with the giant spin Hall effect of tantalum
,”
Science
336
,
555
(
2012
).
4.
L.
Liu
,
T.
Moriyama
,
D. C.
Ralph
, and
R. A.
Buhrman
, “
Spin-torque ferromagnetic resonance induced by the spin Hall effect
,”
Phys. Rev. Lett.
106
,
036601
(
2011
).
5.
W.
Zhang
,
M. B.
Jungfleisch
,
W.
Jiang
,
J.
Sklenar
,
F. Y.
Fradin
,
J. E.
Pearson
,
J. B.
Ketterson
, and
A.
Hoffmann
, “
Spin pumping and inverse spin Hall effects–Insights for future spin-orbitronics (invited)
,”
J. Appl. Phys.
117
,
172610
(
2015
).
6.
A.
Hoffmann
, “
Spin Hall effects in metals
,”
IEEE Trans. Magn.
49
,
5172
(
2013
).
7.
J.
Sinova
,
S. O.
Valenzuela
,
J.
Wunderlich
,
C. H.
Back
, and
T.
Jungwirth
, “
Spin Hall effects
,”
Rev. Mod. Phys.
87
,
1213
(
2015
).
8.
W.
Zhang
,
M. B.
Jungfleisch
,
W.
Jiang
,
J. E.
Pearson
,
A.
Hoffmann
,
F.
Freimuth
, and
Y.
Mokrousov
, “
Spin Hall effects in metallic antiferromagnets
,”
Phys. Rev. Lett.
113
,
196602
(
2014
).
9.
W.
Zhang
,
M. B.
Jungfleisch
,
W.
Jiang
,
Y.
Liu
,
J. E.
Pearson
,
S. G. E.
te Velthuis
,
A.
Hoffmann
,
F.
Freimuth
, and
Y.
Mokrousov
, “
Reduced spin-Hall effects from magnetic proximity
,”
Phys. Rev. B
91
,
115316
(
2015
).
10.
W.
Zhang
,
M. B.
Jungfeisch
,
F.
Freimuth
,
W.
Jiang
,
J.
Sklenar
,
J. E.
Pearson
,
J. B.
Ketterson
,
Y.
Mokrousov
, and
A.
Hoffmann
, “
All-electrical manipulation of magnetization dynamics in a ferromagnet by antiferromagnets with anisotropic spin Hall effects
,”
Phys. Rev. B
92
,
144405
(
2015
).
11.
S.
Fukami
,
C.
Zhang
,
S.
DuttaGupta
,
A.
Kurenkov
, and
H.
Ohno
, “
Magnetization switching by spin-orbit torque in an antiferromagnet-ferromagnet bilayer system
,”
Nat. Mater.
15
,
535
(
2016
).
12.
A.
Manchon
,
H. C.
Koo
,
J.
Nitta
,
S. M.
Frolov
, and
R. A.
Duine
, “
New perspectives for Rashba spin-orbit coupling
,”
Nat. Mater.
14
,
871
(
2015
).
13.
V. M.
Edelstein
, “
Spin polarization of conduction electrons induced by electric current in two-dimensional asymmetric electron systems
,”
Solid State Commun.
73
,
233
(
1990
).
14.
A.
Chernyshov
,
M.
Overby
,
X.
Liu
,
J. K.
Furdyna
,
Y.
Lyanda-Geller
, and
L. P.
Rokhinson
, “
Evidence for reversible control of magnetization in a ferromagnetic material by means of spin-orbit magnetic field
,”
Nat. Phys.
5
,
656
(
2009
).
15.
J. C.
Rojas-Sánchez
,
L.
Vila
,
G.
Desfonds
,
S.
Gambarelli
,
J. P.
Attané
,
J. M.
De Teresa
,
C.
Magén
, and
A.
Fert
, “
Spin-to-charge conversion using Rashba coupling at the interface between non-magnetic materials
,”
Nat. Commun.
4
,
2944
(
2013
).
16.
K.
Chen
and
S.
Zhang
, “
Spin pumping in the presence of spin-orbit coupling
,”
Phys. Rev. Lett.
114
,
126602
(
2015
).
17.
W.
Zhang
,
M. B.
Jungfleisch
,
W.
Jiang
,
J. E.
Pearson
, and
A.
Hoffmann
, “
Spin pumping and inverse Rashba-Edelstein effect in NiFe/Ag/Bi and NiFe/Ag/Sb
,”
J. Appl. Phys.
117
,
17C727
(
2015
).
18.
M. B.
Jungfleisch
,
W.
Zhang
,
J.
Sklenar
,
W.
Jiang
,
J. E.
Pearson
,
J. B.
Ketterson
, and
A.
Hoffmann
, “
Interface-driven spin-torque ferromagnetic resonance by Rashba coupling at the interface between non-magnetic materials
,”
Phys. Rev. B
93
,
224419
(
2016
).
19.
X.
Fan
,
H.
Celik
,
J.
Wu
,
C.
Ni
,
K. J.
Lee
,
V. O.
Lorenz
, and
J. Q.
Xiao
, “
Quantifying interface and bulk contributions to spin-orbit torque in magnetic bilayers
,”
Nat. Commun.
5
,
3042
(
2014
).
20.
A. R.
Mellnik
,
J. S.
Lee
,
A.
Richardella
,
J. L.
Grab
,
P. J.
Mintun
,
M. H.
Fischer
,
A.
Vaezi
,
A.
Manchon
,
E.-A.
Kim
,
N.
Samarth
, and
D. C.
Ralph
, “
Spin-transfer torque generated by a topological insulator
,”
Nature
511
,
449
(
2014
).
21.
Y.
Fan
,
P.
Upadhyaya
,
X.
Kou
,
M.
Lang
,
S.
Takei
,
Z.
Wang
,
J.
Tang
,
L.
He
,
L.-T.
Chang
,
M.
Montazeri
,
G.
Yu
,
W.
Jiang
,
T.
Nie
,
R. N.
Schwartz
,
Y.
Tserkovnyak
, and
K. L.
Wang
, “
Magnetization switching through giant spin-orbit torque in a magnetically doped topological insulator heterostructure
,”
Nat. Mater.
13
,
699
(
2014
).
22.
J.-C.
Rojas-Sánchez
,
S.
Oyarzun
,
F.
Yu
,
A.
Marty
,
C.
Vergnaud
,
S.
Gambarelli
,
L.
Vila
,
M.
Jamet
,
Y.
Ohtsubo
,
A.
Taleb-Ibrahimi
,
P.
Le èvre
,
F.
Bertran
,
N.
Reyren
,
J.-M.
George
, and
A.
Fert
, “
Spin to charge conversion at room temperature by spin pumping into a new type of topological insulator: α-Sn films
,”
Phys. Rev. Lett.
116
,
096602
(
2016
).
23.
D.
Xiao
,
G. B.
Liu
,
W.
Feng
,
X.
Xu
, and
Y.
Wang
, “
Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
,”
Phys. Rev. Lett.
108
,
196802
(
2012
).
24.
H.
Yuan
et al, “
Zeeman-type spin splitting controlled by an electric field
,”
Nat. Phys.
9
,
563
(
2013
).
25.
W.
Zhang
,
J. N.
Sklenar
,
B.
Hsu
,
W.
Jiang
,
M. B.
Jungfleisch
,
J.
Xiao
,
F. Y.
Fradin
,
Y.
Liu
,
J. E.
Pearson
,
J. B.
Ketterson
,
Z.
Yang
, and
A.
Hoffmann
, “
Research update: Spin transfer torques in Py on monolayer MoS2
,”
APL Mater.
4
,
032302
(
2016
).
26.
A. T.
Neal
,
Y.
Du
,
H.
Liu
, and
P. D.
Ye
, “
Two-dimensional TaSe2 metallic crystals: Spin-orbit scattering length and breakdown current density
,”
ACS Nano
8
,
9137
(
2014
).
27.
S.
Sangiao
,
J. M.
De Teresa
,
L.
Morellon
,
I.
Lucas
,
M. C.
Martinez-Velarte
, and
M.
Viret
, “
Control of the spin to charge conversion using the inverse Rashba-Edelstein effect
,”
Appl. Phys. Lett.
106
,
172403
(
2015
).
28.
M.
Isasa
,
M. C.
Martínez-Velarte
,
E.
Villamor
,
C.
Magén
,
L.
Morellón
,
J. M.
De Teresa
,
M. R.
Ibarra
,
G.
Vignale
,
E. V.
Chulkov
,
E. E.
Krasovskii
,
L. E.
Hueso
, and
F.
Casanova
, “
Detection of inverse Rashba-Edelstein effect at Cu/Bi interface using lateral spin valves
,”
Phys. Rev B
93
,
014420
(
2016
).
29.
A.
Nomura
,
T.
Tashiro
,
H.
Nakayama
, and
K.
Ando
, “
Temperature dependence of inverse Rashba-Edelstein effect at metallic interface
,”
Appl. Phys. Lett.
106
,
212403
(
2015
).
30.
C. R.
Ast
,
J.
Henk
,
A.
Ernst
,
L.
Moreschini
,
M. C.
Falub
,
D.
Pacilé
,
P.
Bruno
,
K.
Kern
, and
M.
Grioini
, “
Giant spin splitting through surface alloying
,”
Phys. Rev. Lett.
98
,
186807
(
2007
).
31.
Y. M.
Koroteev
,
G.
Bihlmayer
,
J. E.
Gayone
,
E. V.
Chulkov
,
S.
Blügel
,
P. M.
Echenique
, and
Ph.
Hofmann
, “
Strong spin-orbit splitting on Bi surfaces
,”
Phys. Rev. Lett.
93
,
046403
(
2004
).
32.
J.
Sklenar
,
W.
Zhang
,
M. B.
Jungfleisch
,
W.
Jiang
,
H.
Saglam
,
J. E.
Pearson
,
J. B.
Ketterson
, and
A.
Hoffmann
, “
Spin Hall effects in metallic antiferromagnets—Perspectives for future spin-orbitronics
,”
AIP Adv.
6
,
055603
(
2016
).
33.
D.
Culcer
and
R.
Winkler
, “
Generation of spin currents and spin densities in systems with reduced symmetry
,”
Phys. Rev. Lett.
99
,
226601
(
2007
).
34.
D.
MacNeill
,
G. M.
Stiehl
,
M. H. D.
Guimaraes
,
R. A.
Buhrman
,
J.
Park
, and
D. C.
Ralph
, “
Control of spin-orbit torques through crystal symmetry in WTe2/ferromagnet bilayers
,”
Nat. Phys.
(published online,
2016
).
35.
F.
Meier
,
H.
Dil
,
J.
Lobo-Checa
,
L.
Patthey
, and
J.
Osterwalder
, “
Quantitative vectorial spin analysis in angle-resolved photoemission: Bi/Ag(111) and Pb/Ag(111)
,”
Phys. Rev. B
77
,
165431
(
2008
).
36.
L.
Moreschini
,
A.
Bendounan
,
I.
Gierz
,
C. R.
Ast
,
H.
Mirhosseini
,
H.
Hochst
,
K.
Kern
,
J.
Hen
,
A.
Ernst
,
S.
Ostanin
,
F.
Reinert
, and
M.
Grioni
, “
Assessing the atomic contribution to the Rashba spin-orbit splitting in surface alloys: Sb/Ag(111)
,”
Phys. Rev. B
79
,
075424
(
2009
).
37.
G.
Bian
,
X.
Wang
,
T.
Miller
, and
T.-C.
Chiang
, “
Origin of giant Rashba spin splitting in Bi/Ag surface allows
,”
Phys. Rev. B
88
,
085427
(
2013
).
38.
F.
Hellman
,
A.
Hoffmann
,
Y.
Tserkovnyak
,
G. S. D.
Beach
,
E. E.
Fullerton
,
C.
Leighton
,
A. H.
MacDonald
,
D. C.
Ralph
,
D.
Arena
,
H. A.
Dürr
,
P.
Fischer
,
J.
Grollier
,
J. P.
Heremans
,
T.
Jungwirth
,
A. V.
Kimel
,
B.
Koopmans
,
I. N.
Krivorotov
,
S. J.
May
,
A. K.
Petford-Long
,
J. M.
Rondinelli
,
N.
Samarth
,
I. K.
Schuller
,
A. N.
Slavin
,
M. D.
Stiles
,
O.
Tchernushov.
,
A.
Thiaville
, and
B. L.
Zink
, “
Interface-induced phenomena in magnetism
,” e-print arXiv:1607.00439.
39.
I. M.
Miron
,
G.
Gaudin
,
S.
Auffret
,
B.
Rodmacq
,
A.
Schuhl.
,
S.
Pizzini
,
J.
Vogel
, and
P.
Gambardella
, “
Current-driven spin torque induced by the Rashba effect in a ferromagnetic metal layer
,”
Nat. Mater.
9
,
230
(
2010
).
40.
L.
Wang
,
R. J. H.
Wesselink
,
Y.
Liu
,
Z.
Yuan
,
K.
Xia
, and
P. J.
Kelly
, “
Giant room temperature interface spin Hall and inverse spin Hall effects
,”
Phys. Rev. Lett.
116
,
196602
(
2016
).
41.
Y.
Zhang
,
K.
He
,
C.-Z.
Chang
,
C.-L.
Song
,
L.-L.
Wang
,
X.
Chen
,
J.-F.
Jia
,
Z.
Fang
,
X.
Dai
,
W.-Y.
Shan
,
S.-Q.
Shen
,
Q.
Niu
,
X.-L.
Qi
,
S.-C.
Zhang
,
X.-C.
Ma
, and
Q.-K.
Xue
, “
Crossover of the three-dimensional topological insulator Bi2Se3 to the two-dimensional limit
,”
Nat. Phys.
6
,
584
(
2010
).
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