Spin relaxation times in disordered graphene

TL;DR

This paper analyzes two mechanisms of spin relaxation in disordered graphene, deriving analytical expressions and estimating relaxation times, concluding that spin coherence can be maintained over micron-scale samples due to weak relaxation effects.

Contribution

The study provides analytical formulas for spin relaxation times in disordered graphene considering curvature-induced spin orbit coupling and magnetic edge interactions, with realistic estimates.

Findings

Spin relaxation times are very long, allowing spin coherence up to 1 micron.

Both relaxation mechanisms are weak under realistic conditions.

Spin coherence in disordered graphene is feasible for micron-scale devices.

Abstract

We consider two mechanisms of spin relaxation in disordered graphene. i) Spin relaxation due to curvature spin orbit coupling caused by ripples. ii) Spin relaxation due to the interaction of the electronic spin with localized magnetic moments at the edges. We obtain analytical expressions for the spin relaxation times, tau_SO and tau_J due to both mechanisms and estimate their values for realistic parameters of graphene samples. We obtain that spin relaxation originating from these mechanisms is very weak and spin coherence is expected in disordered graphene up to samples of length L ~ 1 micron.