Energy transfer to acoustic phonons is the dominant low-temperature cooling channel of electrons in a crystal.For cold neutral graphene we find that the weak cooling power of its acoustical modes relative to the heat capacity of the system leads to a power law decay of the electronic temperature when far from equilibrium. For heavily doped graphene a high electronic temperature is shown to initially decrease linearly with time at a rate proportional to n^(3/2) with n being the electronic density. We discuss the relative importance of optical and acoustic phonons to cooling.
@article{arxiv.0901.4159,
title = {Electronic Cooling in Graphene},
author = {R. Bistritzer and A. H. MacDonald},
journal= {arXiv preprint arXiv:0901.4159},
year = {2013}
}