Fermi velocity renormalization in doped graphene

We present an ab initio study of the graphene quasi-particle band structure within GW approximation. In particular we studied the renormalization of the Fermi Velocity V-F as function of the electrostatic doping. We show that within local density approximation (LDA) the Fermi velocity is substantially renormalized by correlation effects and that this renormalization rapidly decreases with doping. We discuss our results in the light of recent experiments on graphene and intercalate graphite. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim