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

TL;DR

This paper introduces a simplified plasmon-pole approximation method for calculating many-body effects in doped graphene, achieving results comparable to complex $GW$-RPA calculations and discussing experimental implications.

Contribution

The paper develops and validates a plasmon-pole approximation scheme for extrinsic graphene's self-energy, simplifying calculations while maintaining accuracy.

Findings

PPA results agree well with full $GW$-RPA calculations.

PPA offers a computationally efficient alternative for many-body effects.

Comparison with hydrodynamic approximation highlights differences in modeling.

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.