Disorder effects on the spin-Hall current in a diffusive Rashba two-dimensional heavy-hole system

TL;DR

This paper studies how different types of disorder affect the spin-Hall current in a two-dimensional heavy-hole system with Rashba spin-orbit coupling, revealing that long-range disorder enhances the effect at high densities and temperature decreases conductivity.

Contribution

It provides a detailed analysis of disorder effects on spin-Hall current in heavy-hole systems, highlighting the role of long-range scatterings and temperature dependence.

Findings

Long-range disorder enhances spin-Hall current at high densities.

Short-range disorder results in negligible contribution to spin-Hall current.

Spin-Hall conductivity decreases as temperature increases.

Abstract

We investigate the spin-Hall effect in a two-dimensional heavy-hole system with Rashba spin-orbit coupling using a nonequilibrium Green's function approach. Both the short- and long-range disorder scatterings are considered in the self-consistent Born approximation. We find that, in the case of long-range collisions, the disorder-mediated process leads to an enhancement of the spin-Hall current at high heavy-hole density, whereas for short-range scatterings it gives a vanishing contribution. This result suggests that the recently observed spin-Hall effect in experiment is a result of the sum of the intrinsic and disorder-mediated contributions. We have also calculated the temperature dependence of spin-Hall conductivity, which reveals a decrease with increasing the temperature.