Spin relaxation related to the edge scattering in graphene

TL;DR

This paper investigates how edge-induced spin-flip scattering affects spin relaxation in graphene nanoribbons, highlighting differences between zigzag and Berry-Mondragon edges and revealing potential for anomalous spin diffusion.

Contribution

It provides a theoretical analysis of edge-related spin-flip scattering effects on spin relaxation times in graphene nanoribbons, considering different edge types and ballistic conditions.

Findings

Zigzag edges can support anomalous spin diffusion due to weak spin-flip scattering.

Spin relaxation times depend on edge type and scattering mechanisms.

Ballistic nanoribbons exhibit distinct spin relaxation behavior influenced by edge scattering.

Abstract

We discuss the role of spin-flip scattering of electrons from the magnetized edges in graphene nanoribbons. The spin-flip scattering is associated with strong fluctuations of the magnetic moments at the edge. Using the Boltzmann equation approach, which is valid for not too narrow nanoribbons, we calculate the spin relaxation time in the case of Berry-Mondragon and zigzag graphene edges. We also consider the case of ballistic nanoribbons characterized by very long momentum relaxation time in the bulk, when the main source of momentum and spin relaxation is the spin-dependent scattering at the edges. We found that in the case of zigzag edges, an anomalous spin diffusion is possible, which is related to very weak spin-flip scattering of electrons gliding along the nanoribbon edge.