Electron-Electron Interactions and Plasmon Dispersion in Graphene

L. S. Levitov, A. V. Shtyk, M. V. Feigelman

Published 2013-02-20, updated 2013-12-18Version 2

Plasmons in two-dimensional electron systems with nonparabolic bands, such as graphene, feature strong dependence on electron-electron interactions. We use a many-body approach to relate plasmon dispersion at long wavelengths to Landau Fermi-liquid interactions and quasiparticle velocity. An identical renormalization is shown to arise for the magnetoplasmon resonance. For a model with N>>1 fermion species, this approach predicts a power-law dependence for plasmon frequency vs. carrier concentration, valid in a wide range of doping densities, both high and low. Gate tunability of plasmons in graphene can be exploited to directly probe the effects of electron-electron interaction.