Current Scaling and Dirac Fermion Heating in Multi-Layer Graphene.

We have performed transport measurements on a multi-layer graphene device fabricated by conventional mechanical exfoliation. By using the zero-field resistance of our graphene device as a self-thermometer, we are able to determine the effective Dirac fermion temperature TDF at various driving currents I while keeping the lattice constant fixed. Interesting, it is found that TDF is proportional to Ia where a ~ 1.