Theory of 2D transport in graphene for correlated disorder

TL;DR

This paper develops a theoretical model for graphene transport that incorporates correlated Coulomb impurity disorder, explaining experimental conductivity behaviors and revealing that impurity correlations can enhance conductivity with increasing impurity density.

Contribution

It introduces a novel theoretical framework accounting for impurity correlations in graphene transport, explaining experimental data and predicting conductivity enhancement due to impurity correlations.

Findings

Impurity correlations cause density-dependent conductivity in graphene.

Conductivity can increase with impurity density if correlations are strong.

Linear and sublinear conductivity regimes are explained by impurity correlations.

Abstract

We theoretically revisit graphene transport properties as a function of carrier density, taking into account possible correlations in the spatial distribution of the Coulomb impurity disorder in the environment. We find that the charged impurity correlations give rise to a density dependent graphene conductivity, which agrees well qualitatively with the existing experimental data. We also find, quite unexpectedly, that the conductivity could increase with increasing impurity density if there is sufficient inter-impurity correlation present in the system. In particular, the linearity (sublinearity) of graphene conductivity at lower (higher) gate voltage is naturally explained as arising solely from impurity correlation effects in the Coulomb disorder.