Conversion of spin current into charge current in a topological insulator: Role of the interface

AbstractA quantum spin Hall (QSH) insulator hosts topological states at the one-dimensional (1D) edge, along which backscattering by nonmagnetic impurities is strictly prohibited. Its 3D analogue, a weak topological insulator (WTI), possesses similar quasi-1D topological states confined at side surfaces. The enhanced confinement could provide a route for dissipationless current and better advantages for applications relative to strong topological insulators (STIs). However, the topological side surface is usually not cleavable and is thus hard to observe. Here, we visualize the topological states of the WTI candidate ZrTe5 by spin and angle-resolved photoemission spectroscopy (ARPES): a quasi-1D band with spin-momentum locking was revealed on the side surface. We further demonstrate that the bulk band gap is controlled by external strain, realizing a more stable WTI state or an ideal Dirac semimetal (DS) state. The highly directional spin-current and the tunable band gap in ZrTe5 will provide an excellent platform for applications.

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Anomalous spin Hall and inverse spin Hall effects in magnetic systems

Communications Physics ◽

10.1038/s42005-021-00557-9 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

X. R. Wang

Keyword(s):

Hall Effect ◽

Order Parameter ◽

Spin Current ◽

Spin Hall Effect ◽

Magnetic Systems ◽

Charge Current ◽

Spin Currents ◽

Tensor Quantity ◽

Hall Effects ◽

Spin Hall Effects

AbstractSpin current is a very important tensor quantity in spintronics. However, the well-known spin-Hall effect (SHE) can only generate a few of its components whose propagating and polarization directions are perpendicular with each other and to an applied charge current. It is highly desirable in applications to generate spin currents whose polarization can be in any possible direction. Here anomalous SHE and inverse spin-Hall effect (ISHE) in magnetic systems are predicted. Spin currents, whose polarisation and propagation are collinear or orthogonal with each other and along or perpendicular to the charge current, can be generated, depending on whether the applied charge current is along or perpendicular to the order parameter. In anomalous ISHEs, charge currents proportional to the order parameter can be along or perpendicular to the propagating or polarization directions of the spin current.

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Pure spin photocurrent in non-centrosymmetric crystals: bulk spin photovoltaic effect

Nature Communications ◽

10.1038/s41467-021-24541-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Haowei Xu ◽

Hua Wang ◽

Jian Zhou ◽

Ju Li

Keyword(s):

Mirror Symmetry ◽

Photovoltaic Effect ◽

Transition Metal Dichalcogenides ◽

Spin Current ◽

Pure Spin ◽

Light Illumination ◽

Metal Dichalcogenides ◽

Critical Components ◽

Topological Crystalline Insulator

AbstractSpin current generators are critical components for spintronics-based information processing. In this work, we theoretically and computationally investigate the bulk spin photovoltaic (BSPV) effect for creating DC spin current under light illumination. The only requirement for BSPV is inversion symmetry breaking, thus it applies to a broad range of materials and can be readily integrated with existing semiconductor technologies. The BSPV effect is a cousin of the bulk photovoltaic (BPV) effect, whereby a DC charge current is generated under light. Thanks to the different selection rules on spin and charge currents, a pure spin current can be realized if the system possesses mirror symmetry or inversion-mirror symmetry. The mechanism of BSPV and the role of the electronic relaxation time $$\tau$$ τ are also elucidated. We apply our theory to several distinct materials, including monolayer transition metal dichalcogenides, anti-ferromagnetic bilayer MnBi2Te4, and the surface of topological crystalline insulator cubic SnTe.

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Spin-current-induced charge current

Physical Review B ◽

10.1103/physrevb.71.125341 ◽

2005 ◽

Vol 71 (12) ◽

Author(s):

Soon-wook Jung ◽

Hyun-Woo Lee

Keyword(s):

Spin Current ◽

Charge Current ◽

Induced Charge

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Conversion of spin current into charge current at room temperature: Inverse spin-Hall effect

Applied Physics Letters ◽

10.1063/1.2199473 ◽

2006 ◽

Vol 88 (18) ◽

pp. 182509 ◽

Cited By ~ 1295

Author(s):

E. Saitoh ◽

M. Ueda ◽

H. Miyajima ◽

G. Tatara

Keyword(s):

Hall Effect ◽

Room Temperature ◽

Spin Current ◽

Spin Hall Effect ◽

Charge Current ◽

Inverse Spin Hall Effect

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The quantum anomalous Hall effect in a topological insulator thin film —The role of magnetic disorder

EPL (Europhysics Letters) ◽

10.1209/0295-5075/105/57004 ◽

2014 ◽

Vol 105 (5) ◽

pp. 57004 ◽

Cited By ~ 8

Author(s):

Shu-guang Cheng

Keyword(s):

Thin Film ◽

Hall Effect ◽

Topological Insulator ◽

Anomalous Hall Effect ◽

Quantum Anomalous Hall Effect ◽

Magnetic Disorder

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Spin Pumping in a Ferromagnetic/Nonmagnetic/Spin-Sink Trilayer Film: Spin Current Termination

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.508.266 ◽

2012 ◽

Vol 508 ◽

pp. 266-270 ◽

Cited By ~ 9

Author(s):

K. Harii ◽

Z. Qiu ◽

T. Iwashita ◽

Y. Kajiwara ◽

K. Uchida ◽

...

Keyword(s):

Diffusion Equation ◽

Hall Effect ◽

Spin Diffusion ◽

Diffusion Length ◽

Spin Current ◽

Interlayer Thickness ◽

Spin Pumping ◽

Charge Current ◽

Inverse Spin Hall Effect ◽

Spin Diffusion Length

A Spin Current Generated by Spin Pumping in a Ferromagnetic/Nonmagnetic/Spin-Sink Trilayer Film Is Calculated Based on the Spin Pumping Theory and the Standard Spin Diffusion Equation. By Attaching the Spin-Sink Layer, the Injected Spin Current Is Drastically Enhanced when the Interlayer Thickness Is Shorter than the Spin Diffusion Length of the Interlayer. We Also Provided the Formula of the Charge Current which Is Induced from the Pumped Spin Current via the Inverse Spin-Hall Effect.

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