Plasmons and the spectral function of graphene

We report a theoretical study of the influence of electron-electron interactions on the one-particle Green's function of a doped graphene sheet based on the random-phase approximation and on graphene's massless Dirac equation continuum model. We find that states near the Dirac point interact strongly with plasmons with a characteristic frequency omega(star)(pl) that scales with the sheet's Fermi energy and depends on its interaction coupling constant alpha(gr), partially explaining prominent features of recent angle-resolved photoemission spectroscopy data.