Semiclassical spin transport in spin-orbit-coupled systems

TL;DR

This paper explores semiclassical methods to understand spin transport in systems with spin-orbit coupling, highlighting the role of wave-packets, spin precession, and scattering in generating and defining spin currents.

Contribution

It introduces a semiclassical wave-packet framework for spin transport and clarifies the relationship between spin currents, precession, and scattering effects.

Findings

Wave-packet description explains microscopic origin of spin currents

Spin non-conservation leads to arbitrariness in defining spin current

Density matrix approach links spin precession with transport phenomena

Abstract

This article discusses spin transport in systems with spin-orbit interactions and how it can be understood in a semiclassical picture. I will first present a semiclassical wave-packet description of spin transport, which explains how the microscopic motion of carriers gives rise to a spin current. Due to spin non-conservation the definition of the spin current has some arbitrariness. In the second part I will briefly review the physics from a density matrix point of view, which makes clear the relationship between spin transport and spin precession and the important role of scattering.