Anisotropic transport in the two-dimensional electron gas in the presence of spin-orbit coupling

TL;DR

This paper investigates how spin-orbit coupling induces anisotropic electrical conductivity in a two-dimensional electron gas, offering a method to detect and analyze spin-orbit effects through measurable electrical currents.

Contribution

It presents an exact solution to the Boltzmann equation to study anisotropic transport caused by Rashba and Dresselhaus spin-orbit coupling in 2D electron gases.

Findings

Conductivity exhibits anisotropy tunable by Rashba coefficient.

Anisotropic Fermi contours influence electrical transport.

Method enables investigation of spin-orbit effects via electrical measurements.

Abstract

In a two-dimensional electron gas as realized by a semiconductor quantum well, the presence of spin-orbit coupling of both the Rashba and Dresselhaus type leads to anisotropic dispersion relations and Fermi contours. We study the effect of this anisotropy on the electrical conductivity in the presence of fixed impurity scatterers. The conductivity also shows in general an anisotropy which can be tuned by varying the Rashba coefficient. This effect provides a method of detecting and investigating spin-orbit coupling by measuring spin-unpolarized electrical currents in the diffusive regime. Our approach is based on an exact solution of the two-dimensional Boltzmann equation and provides also a natural framework for investigating other transport effects including the anomalous Hall effect.