Extrinsic spin Hall effect induced by resonant skew scattering in graphene

TL;DR

This paper demonstrates that the extrinsic spin Hall effect in graphene can be significantly enhanced through resonant skew scattering caused by adatoms or nanoparticles, leading to potentially large spin currents in practical devices.

Contribution

It introduces a method to engineer a strong extrinsic spin Hall effect in graphene via local spin-orbit perturbations from adatoms and analyzes the resulting skew scattering and transport properties.

Findings

Giant spin Hall currents are achievable with current fabrication techniques.

The effect is robust against thermal fluctuations and disorder.

Resonant skew scattering significantly enhances the spin Hall effect.

Abstract

We show that the extrinsic spin Hall effect can be engineered in monolayer graphene by decoration with small doses of adatoms, molecules, or nanoparticles originating local spin-orbit perturbations. The analysis of the single impurity scattering problem shows that intrinsic and Rashba spin-orbit local couplings enhance the spin Hall effect via skew scattering of charge carriers in the resonant regime. The solution of the transport equations for a random ensemble of spin-orbit impurities reveals that giant spin Hall currents are within the reach of the current state of the art in device fabrication. The spin Hall effect is robust with respect to thermal fluctuations and disorder averaging.