Spin accumulation with spin-orbit interaction

TL;DR

This paper reconciles different views on spin accumulation in spintronics by showing how electron-electron interactions, specifically exchange fields, can unify semiclassical and quantum interpretations, demonstrated in a 2DEG.

Contribution

It introduces a self-consistent exchange field framework that unifies semiclassical and quantum descriptions of spin accumulation in systems with strong spin-orbit coupling.

Findings

Exchange field reduces spin accumulation to a chemical potential difference.

Exchange field protects spin accumulation from dephasing.

Introduces easy-plane anisotropy in a 2DEG.

Abstract

Spin accumulation is a crucial but imprecise concept in spintronics. In metal-based spintronics it is characterized in terms of semiclassical distribution functions. In semiconductors with a strong spin-orbit coupling the spin accumulation is interpreted as a superposition of coherent eigenstates. Both views can be reconciled by taking into account the electron-electron interaction: a sufficiently strong self-consistent exchange field reduces a spin accumulation to a chemical potential difference between the two spin bands even in the presence of spin-orbit coupling. We demonstrate the idea on a clean two-dimensional electron gas (2DEG) by showing how the exchange field protects a spin accumulation from dephasing and introduces an easy-plane anisotropy.