APS March Meeting 2017
Volume 62, Number 4
Monday–Friday, March 13–17, 2017;
New Orleans, Louisiana
Session P47: Spin Transport and Topology
2:30 PM–5:30 PM,
Wednesday, March 15, 2017
Room: 394
Sponsoring
Units:
GMAG DMP FIAP
Chair: Eric Edwards, NIST Boulder
Abstract ID: BAPS.2017.MAR.P47.8
Abstract: P47.00008 : Charge-spin conversion at interfaces with spin splitting
4:18 PM–4:54 PM
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Abstract
Author:
kouta kondou
(RIKEN)
The two-dimensional electronic systems with band-splitting like the surface
state of a topological insulator (TI) and Rashba interface provide unique
opportunities for spintronics applications. The spin-momentum locking in the
surface state offers a possibility of a highly efficient charge-spin current
(C-S) interconversion compared with ordinary spin Hall effect in
paramagnetic metals. The interfacial C-S conversion mechanism has been
proposed by Edelstein in 1990 [V. M. Edelstein, Solid State Commun. 73,
233--235 (1990).]. For Ag/Bi Rashba interface, it was recently observed
[J.C. Rojas Sánchez et al, Nat. Commun. 4, 2944 (2013).]. For the further
development of interfacial spin current devices, it is important to
quantitatively evaluate the conversion efficiency between charge and spin
current.
Firstly, we investigated the C-S conversion in surface state of topological
insulators, which are appropriate materials for efficient interfacial C-S
conversion. We prepared the TI ((Bi1-xSbx)2Te3: BST)/non-magnetic metal
(Cu)/ferromagnetic-metal (NiFe) tri-layer films. By applying spectral
analysis based on spin-torque ferromagnetic resonance (ST-FMR) to
BST/Cu/NiFe tri-layer films, we succeeded in determining the C-S conversion
efficiency of a surface state of TIs, whose Fermi level was varied by tuning
the Sb composition. We found that in bulk insulating conditions the
interface C-S conversion effect via Dirac surface state is evaluated as
nearly constant large values [K. Kondou et al., Nat. phys, (2016)
doi:10.1038/nphys3833].
Secondary, we measured S-C conversion effect in non-magnetic metal/oxide
interface. We found the S-C conversion phenomenon in non-magnetic metal
(Cu)/oxide (Bi2O3) interface, which may be caused by Rashba effect like
Ag/Bi interface [K. Karube et al., Appl. Phys. Exp. 9, 033001 (2016).].
Interestingly, the amplitude of S-C conversion efficiency strongly depends
on Cu layer thickness. These findings have important implications for
development of future spintronic devise using the interface spin conversion
effect.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2017.MAR.P47.8