The Role of Electron-electron Interactions in Graphene ARPES Spectra

TL;DR

This paper presents a theoretical analysis of how electron-electron interactions affect ARPES spectra in graphene, revealing interaction-dependent features that could help measure fundamental material parameters.

Contribution

It introduces a model combining the RPA and Dirac equation to explain interaction effects on ARPES spectra in graphene, highlighting a gap-like feature due to level repulsion.

Findings

Level repulsion causes a gap-like feature at small k.

Spectra are sensitive to the interaction strength $ ext{α}_{ ext{gr}}$.

Potential for experimental determination of $ ext{α}_{ ext{gr}}$.

Abstract

We report on a theoretical study of the influence of electron-electron interactions on ARPES spectra in graphene that is based on the random-phase-approximation and on graphene's massless Dirac equation continuum model. We find that level repulsion between quasiparticle and plasmaron resonances gives rise to a gap-like feature at small k. ARPES spectra are sensitive to the electron-electron interaction coupling strength $\alpha_{\rm gr}$ and might enable an experimental determination of this material parameter.