Polarized Electric Current in Semiclassical Transport with Spin-Orbit Interaction

TL;DR

This paper analyzes semiclassical electron transport with spin-orbit interaction, deriving explicit expressions for spin polarization and demonstrating how to generate spin-polarized currents using barriers or quantum point contacts.

Contribution

It provides a new semiclassical framework for understanding spin polarization and current generation in two-dimensional systems with spin-orbit coupling.

Findings

In-plane spin polarization follows electron momentum evolution.

Out-of-plane spin polarization appears as a quantum correction.

Spin-polarized currents can be achieved with barriers or quantum point contacts.

Abstract

Semiclassical solutions of two-dimensional Schrodinger equation with spin-orbit interaction and smooth potential are considered. In the leading order, spin polarization is in-plane and follows the evolution of the electron momentum for a given subband. Out-of-plane spin polarization appears as a quantum correction, for which an explicit expression is obtained. We demonstrate how spin-polarized currents can be achieved with the help of a barrier or quantum point contact open for transmission only in the lower subband.