Ab-initio band structure of doped graphene

TL;DR

This paper uses ab-initio calculations to study how doping affects the electronic band structure of graphene, revealing significant renormalization of Fermi velocity and changes in linear dispersion near the Dirac point.

Contribution

It provides a detailed ab-initio analysis of doping effects on graphene's band structure, including Fermi velocity renormalization and dispersion behavior near the Dirac point.

Findings

Fermi velocity is substantially renormalized by doping

Linear dispersion near the Dirac point is broken at low doping

Renormalization decreases rapidly with increased doping

Abstract

We present an \emph{ab-initio} study of the graphene quasi-particle band structure as function of the doping in G_0 W_0 approximation. We show that the LDA Fermi velocity is substantially renormalized and this renormalization rapidly decreases as function of the doping. We found, in agreement with previous papers, that close to the Dirac point the linear dispersion of the bands is broken but this behaviour disappears with a small doping. We discuss our results in the light of recent experiments on graphene and intercalate graphite.