Inverse Spin Hall Effect Induced by Asymmetric Illumination of Light on Topological Insulator Bi${}_2$Se${}_3$

Abstract

Using circularly polarized light is an alternative to electronic ways for spin injection into materials. Spins are injected at a point of the light illumination, and then diffuse and spread radially due to the in-plane gradient of the spin density. This diffusion is converted into a circular charge current by the inverse spin Hall effect (ISHE). With shining the circularly polarized light at asymmetric parts of the sample, such as near edges, we detected this current as a helicity-dependent component in the photocurrent. We present a model for this ISHE based on the experimental results and the finite-element-method (FEM) simulation of the potential distribution induced by spin injection. Our model shows that the ISHE photocurrent generates an electric dipole at the edge of the sample, causing the measured charge current. The asymmetric light-illumination shown here is a simple way to inject and manipulate spins, opening up a door for novel spintronic devices.

References in corpus (12)

• Room Temperature Reversible Spin Hall Effect
• Control over topological insulator photocurrents with light polarization
• Large tuneable Rashba spin splitting of a two-dimensional electron gas in Bi2Se3
• Spin-pumping into surface states of topological insulator α-Sn, spin to charge conversion at room temperature
• Generation and Electric Control of Spin-Coupled Valley Current in WSe2
• Observation of a warped helical spin-texture in Bi${}_2$Se${}_3$ from circular dichroism angle-resolved photoemission spectroscopy
• Spatially resolved femtosecond pump-probe study of topological insulator Bi2Se3
• Enhanced photogalvanic current in topological insulators via Fermi energy tuning
• Optical orientation of electron spins in GaAs quantum wells
• Spin Hall effects in diffusive normal metals
• Spin Hall photoconductance in a 3D topological insulator at room temperature
• Rashba-driven anomalous Nernst conductivity of lead chalcogenide films

Cited by in corpus (3)

• Topological nature of the proper spin current and the spin-Hall torque
• Band Structure and Polarization Effects in Photothermoelectric Spectroscopy of a Bi2Se3 Device
• Surface Circular Photogalvanic Effect in Tl-Pb Monolayer Alloys on Si(111) with Giant Rashba Splitting