Spin-charge coupling effects in a two-dimensional electron gas

TL;DR

This paper investigates the effects of Rashba spin-orbit coupling on a disordered two-dimensional electron gas using advanced Green function techniques, deriving a generalized Boltzmann equation to analyze spin-related phenomena.

Contribution

It introduces a formalism that incorporates intrinsic and extrinsic spin-orbit effects into a unified Boltzmann equation framework for 2D electron gases.

Findings

Derived a generalized Boltzmann equation including spin and charge dynamics.

Analyzed spin Hall and Edelstein effects within the formalism.

Included extrinsic effects like side jump, skew scattering, and spin current swapping.

Abstract

In these lecture notes we study the disordered two-dimensional electron gas in the presence of Rashba spin-orbit coupling, by using the Keldysh non-equilibrium Green function technique. We describe the effects of the spin-orbit coupling in terms of a SU(2) gauge field and derive a generalized Boltzmann equation for the charge and spin distribution functions. We then apply the formalism to discuss the spin Hall and the inverse spin galvanic (Edelstein) effects. Successively we show how to include, within the generalized Boltzmann equation, the side jump, the skew scattering and the spin current swapping processes originating from the extrinsic spin-orbit coupling due to impurity scattering.