Interplay of intrinsic and extrinsic mechanisms to the spin Hall effect in a two-dimensional electron gas

TL;DR

This paper investigates how intrinsic and extrinsic spin-orbit interactions influence the spin Hall effect in a two-dimensional electron gas, emphasizing the importance of different spin relaxation mechanisms and their ratios.

Contribution

It introduces a comprehensive model that incorporates both Dyakonov-Perel and Elliot-Yafet spin relaxation times to accurately describe the spin Hall conductivity.

Findings

Spin Hall conductivity depends on the ratio of spin relaxation times.

Both intrinsic and extrinsic mechanisms significantly affect the spin Hall effect.

The model clarifies the interplay between different spin relaxation processes.

Abstract

In order to describe correctly the interplay of extrinsic and intrinsic spin-orbit mechanisms to the spin Hall effect, it is necessary to consider different sources of spin relaxation. We take into account the spin relaxation time $\tau_{DP}$ due to the Dyakonov-Perel mechanism as well as the Elliot-Yafet spin-relaxation time $\tau_s$ due to the spin-orbit scattering from impurities. The total spin Hall conductivity depends crucially on the ratio $\tau_s /\tau_{DP}$.