Spin Filtered Edge States and Quantum Hall Effect in Graphene

TL;DR

This paper explores spin-polarized edge states in graphene under Quantum Hall conditions, revealing how spin splitting creates counterpropagating modes with potential for spin current control.

Contribution

It demonstrates the formation of spin-polarized edge states due to Landau level splitting and proposes a method to control spin flip rates locally in graphene.

Findings

Counterpropagating spin modes arise from Landau level splitting.

A spin gap of a few hundred Kelvin is estimated.

A method for local control of spin flip rates is proposed.

Abstract

Electron edge states in graphene in the Quantum Hall effect regime can carry both charge and spin. We show that spin splitting of the zeroth Landau level gives rise to counterpropagating modes with opposite spin polarization. These chiral spin modes lead to a rich variety of spin current states, depending on the spin flip rate. A method to control the latter locally is proposed. We estimate Zeeman spin splitting enhanced by exchange, and obtain a spin gap of a few hundred Kelvin.