We calculate the conductivity of a clean graphene sheet at finite temperatures starting from the tight-binding model. We obtain a finite value for the dc-conductivity at zero temperature. For finite temperature, the spontaneous electron-hole creation, responsible for the finite conductivity at zero temperature, is washed out and the dc-conductivity yields zero. Our results are in agreement with calculations based on the field-theoretical model for graphene.
@article{arxiv.0801.1519,
title = {Transport in a Clean Graphene Sheet at Finite Temperature and Frequency},
author = {N. M. R. Peres and T. Stauber},
journal= {arXiv preprint arXiv:0801.1519},
year = {2008}
}