The quasiparticle spectral function in doped graphene

TL;DR

This paper presents a theoretical calculation of the quasiparticle spectral function in doped graphene, incorporating electron-electron interactions, and compares the results with experimental ARPES data, confirming Fermi liquid behavior.

Contribution

The study provides a comprehensive theoretical framework for all one-electron properties of extrinsic graphene considering dynamically screened Coulomb interactions.

Findings

Qualitative agreement with ARPES measurements

Identification of Fermi liquid discontinuity at k_F

Analysis of many-body approximation validity

Abstract

We calculate the real and imaginary electron self-energy as well as the quasiparticle spectral function in doped graphene taking into account electron-electron interaction in the leading order dynamically screened Coulomb coupling. Our theory provides the basis for calculating {\it all} one-electron properties of extrinsic graphene. Comparison with existing ARPES measurements shows broad qualitative agreement between theory and experiment. We also calculate the renormalized graphene momentum distribution function, finding a typical Fermi liquid discontinuity at k_F. We also provide a critical discussion of the relevant many body approximations (e.g. RPA) for graphene.