Electronic cooling in graphene

Phys Rev Lett. 2009 May 22;102(20):206410. doi: 10.1103/PhysRevLett.102.206410. Epub 2009 May 21.


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 acoustic modes relative to their heat capacity 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. The temperature at which cooling via optical phonon emission begins to dominate depends on graphene carrier density.