Generating Spin Currents in Semiconductors with the Spin Hall Effect

TL;DR

This paper demonstrates the generation of spin currents in GaAs semiconductors via the spin Hall effect, using Kerr microscopy to visualize spin accumulation and modeling to quantify spin drift velocities.

Contribution

It provides experimental evidence of bulk spin currents driven by the spin Hall effect in semiconductors, distinguishing edge effects from bulk transport.

Findings

Spin accumulation extends nearly 40 microns into regions with minimal electric field.

Transverse spin drift velocity is quantified through magnetic field dependence.

Spin currents are generated and detected using Kerr rotation microscopy.

Abstract

We investigate electrically-induced spin currents generated by the spin Hall effect in GaAs structures that distinguish edge effects from spin transport. Using Kerr rotation microscopy to image the spin polarization, we demonstrate that the observed spin accumulation is due to a transverse bulk electron spin current, which can drive spin polarization nearly 40 microns into a region in which there is minimal electric field. Using a model that incorporates the effects of spin drift, we determine the transverse spin drift velocity from the magnetic field dependence of the spin polarization.