Ground-state of graphene in the presence of random charged impurities

TL;DR

This paper presents a self-consistent theoretical study of how random charged impurities affect the ground state and carrier density distribution in graphene, revealing significant inhomogeneity at low densities.

Contribution

It introduces a non-perturbative, self-consistent approach to analyze disorder and interaction effects on graphene's ground state properties.

Findings

Disorder causes significant inhomogeneity in carrier density at low densities.

Density fluctuations can exceed the average density in typical samples.

Interplay between disorder and interaction is particularly strong at low impurity densities.

Abstract

We calculate the carrier density dependent ground state properties of graphene in the presence of random charged impurities in the substrate taking into account disorder and interaction effects non-perturbatively on an equal footing in a self-consistent theoretical formalism. We provide detailed quantitative results on the dependence of the disorder-induced spatially inhomogeneous two-dimensional carrier density distribution on the external gate bias, the impurity density, and the impurity location. We find that the interplay between disorder and interaction is strong, particularly at lower impurity densities. We show that for the currently available typical graphene samples, inhomogeneity dominates graphene physics at low ($\lesssim 10^{12}$ cm$^{-2}$) carrier density with the density fluctuations becoming larger than the average density.