Plasmons and their interaction with electrons in trilayer graphene

The interaction between electrons and plasmons in trilayer graphene is investigated within the Overhauser approach resulting in the "plasmaron" quasiparticle. This interaction is cast into a field theoretical problem, and its effect on the energy spectrum is calculated using improved Wigner-Brillouin perturbation theory. The plasmaron spectrum is shifted with respect to the bare electron spectrum by Delta E(k) similar to 150-200 meV for ABC stacked trilayer graphene and for ABA trilayer graphene by Delta E(k) similar to 30-150 meV [Delta E(k) similar to 1-5 meV] for the hyperbolic (linear) part of the spectrum. The shift in general increases with the electron concentration ne and electron momentum. The dispersion of plasmarons is more pronounced in ABC stacked than in ABA stacked trilayer graphene, because of the different energy band structure and their different plasmon dispersion