Weak localization in monolayer and bilayer graphene

TL;DR

This paper investigates how disorder and Fermi surface warping affect weak localization phenomena in monolayer and bilayer graphene, revealing suppression and restoration mechanisms of localization effects.

Contribution

It provides a detailed theoretical analysis of weak localization corrections considering trigonal warping and intervalley scattering in graphene.

Findings

Trigonal warping suppresses weak anti-localization in monolayer graphene.

Intervalley scattering restores weak localization, leading to negative magnetoresistance.

Disorder and edges influence localization behavior in graphene sheets.

Abstract

We describe the weak localization correction to conductivity in ultra-thin graphene films, taking into account disorder scattering and the influence of trigonal warping of the Fermi surface. A possible manifestation of the chiral nature of electrons in the localization properties is hampered by trigonal warping, resulting in a suppression of the weak anti-localization effect in monolayer graphene and of weak localization in bilayer graphene. Intervalley scattering due to atomically sharp scatterers in a realistic graphene sheet or by edges in a narrow wire tends to restore weak localization resulting in negative magnetoresistance in both materials.