The quasiparticle lifetime in a doped graphene sheet

摘要

We present a calculation of the quasiparticle decay rate due toelectron-electron interactions in a doped graphene sheet. In particular, weemphasize subtle differences between the perturbative calculation of thisquantity in a doped graphene sheet and the corresponding one in ordinaryparabolic-band two-dimensional (2D) electron liquids. In the random phaseapproximation, dynamical overscreening near the light cone yields a universalquasiparticle lifetime, which is independent of the dielectric environmentsurrounding the 2D massless Dirac fermion fluid.