Ground State Properties of Monolayer Doped Graphene

Abstract

We performed theoretical investigations on self-energy, screening charge density, screened potential and pair distribu- tion function for a doped single layer graphene. Random phase approximation density-density response function and graphene’s massless Diracfermions concept have been used in our calculations. Local field effects have been included using Hubbard approximation to go beyond random phase approximation. Ultraviolet wave vector cutoff has been used to exclude the effect of vacuum states. Our computed self energy of graphene though displays a behavour similar to that of 2DEG, its magnitude differs drastically from that of 2DEG. Freidel oscillations are seen in computed screened potential and density of screening charge of graphene, which can be seen as a signature of Fermi liquid state in doped graphene. In agreement with experimental results, our computed pair distribution function, as a function of carrier density, suggests that exchange and correlation terms make negligible contribution to compressibility of graphene. Incorporation of LFC reduces the magnitude of self energy, screening charge density and screened potential.