Inelastic carrier lifetime in graphene

We consider hot-carrier inelastic scattering due to electron-electron interactions in graphene as functions of carrier energy and density. We calculate the imaginary part of the zero-temperature quasiparticle self-energy for doped graphene utilizing the G(0)W and random phases approximations. Using the full dynamically screened Coulomb interaction, we obtain the inelastic quasiparticle lifetimes and associated mean free paths. The linear dispersion of graphene gives lifetime energy dependences that are qualitatively different from those of parabolic-band semiconductors. We also get good agreement with data from angle-resolved photoemission spectroscopy experiments.