Voltage-induced suppression of weak localization in graphene

TL;DR

This theoretical study demonstrates that applying a voltage to weakly-disordered graphene suppresses weak localization effects by inducing a voltage-dependent dephasing time, affecting quantum interference and transport properties.

Contribution

We introduce a nonequilibrium Green function approach to analyze how voltage suppresses weak localization in graphene, incorporating disorder scattering and interference effects.

Findings

Voltage suppresses weak localization in graphene.

Dephasing time decreases inversely with increasing voltage.

Logarithmic divergence in conductance is affected by applied voltage.

Abstract

In this theoretical study, we explore the manner in which the quantum correction due to weak localization is suppressed in weakly-disordered graphene, when it is subjected to the application of a non-zero voltage. Using a nonequilibrium Green function approach, we address the scattering generated by the disorder up to the level of the maximally crossed diagrams, hereby capturing the interference among different, impurity-defined, Feynman paths. Our calculations of the charge current, and of the resulting differential conductance, reveal the logarithmic divergence typical of weak localization in linear transport. The main finding of our work is that the applied voltage suppresses the weak localization contribution in graphene, by introducing a dephasing time that decreases inversely with increasing voltage.