Energy-momentum dispersion relation of plasmarons in graphene

Abstract

The many-body correction to the band structure of a quasi-free-standing graphene layer is obtained within the Overhauser approach, where the electron-plasmon interaction is described as a field theoretical problem. We find that the Dirac-like spectrum is shifted by $\ensuremath{\Delta}E(\mathbf{k}=0)$, which is on the order of 50--150 meV, depending on the electron concentration ${n}_{e}$, and is in semiquantitative agreement with experimental data. The value of the Fermi velocity is renormalized by several percents and decreases with increasing electron concentration as found experimentally.