Screening-induced temperature-dependent transport in two-dimensional graphene

We calculate the temperature-dependent conductivity of graphene in the presence of randomly distributed Coulomb impurity charges arising from the temperature-dependent screening of the Coulomb disorder without any phonons. The purely electronic temperature dependence of our theory arises from two independent mechanisms: the explicit temperature dependence of the finite-temperature dielectric function ε (q,T) and the finite-temperature energy averaging of the transport scattering time. We find that the calculated temperature-dependent conductivity is nonmonotonic, decreasing with temperature at low temperatures, and increasing at high temperatures. We provide a critical comparison with the corresponding physics in semiconductor-based parabolic band 2D electron-gas systems.