Kinetic investigation on extrinsic spin Hall effect induced by skew scattering

TL;DR

This paper investigates the microscopic kinetics of the extrinsic spin Hall effect in GaAs quantum wells, revealing the roles of spin-orbit coupling and spin precession in the steady-state behavior and spin polarization.

Contribution

It provides a detailed kinetic analysis of the extrinsic spin Hall effect induced by skew scattering, highlighting the impact of spin-orbit coupling and spin precession on the effect's magnitude and spin polarization.

Findings

Extrinsic spin Hall conductivity vanishes for linear-$ extbf{k}$ spin-orbit coupling.

Conductivity is very small for cubic-$ extbf{k}$ spin-orbit coupling.

In-plane spin polarization is induced by skew scattering, distinct from current-induced polarization.

Abstract

The kinetics of the extrinsic spin Hall conductivity induced by the skew scattering is performed from the fully microscopic kinetic spin Bloch equation approach in $(001)$ GaAs symmetric quantum well. In the steady state, the extrinsic spin Hall current/conductivity vanishes for the linear-$\mathbf k$ dependent spin-orbit coupling and is very small for the cubic-$\mathbf k$ dependent spin-orbit coupling. The spin precession induced by the Dresselhaus/Rashba spin-orbit coupling plays a very important role in the vanishment of the extrinsic spin Hall conductivity in the steady state. An in-plane spin polarization is induced by the skew scattering, with the help of the spin-orbit coupling. This spin polarization is very different from the current-induced spin polarization.