Plasmon-pole approximation for many-body-effects in extrinsic graphene

Abstract

We develop the plasmon-pole approximation (PPA) theory for calculating the carrier self-energy of extrinsic graphene as a function of doping density within analytical approximations to the $GW$ random phase approximation ($GW$-RPA). Our calculated self-energy shows excellent quantitative agreement with the corresponding full $GW$-RPA calculation results in spite of the simplicity of the PPA, establishing the general validity of the plasmon-pole approximation scheme. We also provide a comparison between the PPA and the hydrodynamic approximation in graphene, and comment on the experimental implications of our findings.

13 pages, 9 figures. Expanded discussions of the use of PPA as a numerical approximation compared with other approximations and clarified that we are developing an analytical approximation for graphene. Combined Figs. 2-5 into a single figure. Published in Phys. Rev. B; this is the published version