Intrinsic Spin Hall Effect in the Two Dimensional Hole Gas

TL;DR

This paper demonstrates that intrinsic spin Hall effects arise from spin-orbit coupling in two-dimensional hole gases, with impurity scattering effects being negligible, and connects theoretical predictions with recent experimental observations in GaAs semiconductors.

Contribution

It shows that spin-orbit coupling causes intrinsic spin Hall effects in 2D hole gases and that impurity vertex corrections vanish, supporting the intrinsic nature of observed effects.

Findings

Spin-orbit coupling induces intrinsic spin Hall effect in 2DHG.

Impurity vertex corrections vanish in both inversion symmetric and asymmetric cases.

Experimental observations in GaAs align with the intrinsic spin Hall effect theory.

Abstract

We show that two types of spin-orbit coupling in the 2 dimensional hole gas (2DHG), with and without inversion symmetry breaking, contribute to the intrinsic spin Hall effect\cite{murakami2003,sinova2003}. Furthermore, the vertex correction due to impurity scattering vanishes in both cases, in sharp contrast to the case of usual Rashba coupling in the electron band. Recently, the spin Hall effect in a hole doped $GaAs$ semiconductor has been observed experimentally by Wunderlich \emph{et al}\cite{wunderlich2004}. From the fact that the life time broadening is smaller than the spin splitting, and the fact impurity vertex corrections vanish in this system, we argue that the observed spin Hall effect should be in the intrinsic regime.