Diffuse transport and spin accumulation in a Rashba two-dimensional electron gas

TL;DR

This paper derives the diffusive conductance tensor for a disordered Rashba 2D electron gas, showing bias-induced spin accumulation without spin-polarized current, advancing understanding of spin transport in spin-orbit coupled systems.

Contribution

It provides a detailed derivation of the conductance tensor and clarifies the relationship between bias, spin accumulation, and current polarization in Rashba systems.

Findings

Bias induces spin accumulation in the 2D electron gas.

Electric current remains unpolarized despite spin accumulation.

Derived conductance tensor clarifies spin transport mechanisms.

Abstract

The Rashba Hamiltonian describes the splitting of the conduction band as a result of spin-orbit coupling in the presence of an asymmetric confinement potential and is commonly used to model the electronic structure of confined narrow-gap semiconductors. Due to the mixing of spin states some care has to be exercised in the calculation of transport properties. We derive the diffusive conductance tensor for a disordered two-dimensional electron gas with spin-orbit interaction and show that the applied bias induces a spin accumulation, but that the electric current is not spin-polarized.