Edge Spin Current and Spin Polarization in Quantum Hall Regime

TL;DR

This paper investigates how edge effects influence spin currents and polarization in a quantum Hall system with spin-orbit coupling, revealing large edge spin currents and their relation to spin polarization.

Contribution

It demonstrates the impact of edge effects on Landau level degeneracy and spin transport, highlighting the proportionality between spin current and spin polarization in the quantum Hall regime.

Findings

Large edge spin currents are observed when Landau levels degenerate.

Spin current is proportional to spin polarization along the y-axis.

Edge effects remove bulk Landau level degeneracy.

Abstract

We study the edge spin current and spin polarization in a two-dimensional electron gas with spin-orbit coupling in the presence of a perpendicular magnetic field. The edge effect removes the degeneracy of Landau levels due to the competition between the Rashba coupling and the Zeeman splitting, which exists in the bulk. Large spin edge current and non-linear response to an electric field are found when the two levels are degenerated in the bulk. It is found that he spin current is proportional to spin polarization along the y-direction in an finite magnetic field, which provides a way to extract the spin current in the system.