Resonant scattering by realistic impurities in graphene

TL;DR

This paper presents a first-principles theory for resonant impurities in graphene, showing how realistic impurities create midgap states and affect conductivity, aligning with experimental observations.

Contribution

It introduces a comprehensive first-principles framework to understand how realistic impurities influence graphene's electronic transport properties.

Findings

Realistic impurities induce midgap states near the neutrality point.

Theoretical conductivity matches recent experimental results.

Impurities cause a sublinear dependence of conductivity on carrier concentration.

Abstract

We develop a first-principles theory of resonant impurities in graphene and show that a broad range of typical realistic impurities leads to the characteristic sublinear dependence of the conductivity on the carrier concentration. By means of density functional calculations various organic groups as well as ad-atoms like H absorbed to graphene are shown to create midgap states within +-0.03eV around the neutrality point. A low energy tight-binding description is mapped out. Boltzmann transport theory as well as a numerically exact Kubo formula approach yield the conductivity of graphene contaminated with these realistic impurities in accordance with recent experiments.