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 ∝ I ^α, where α∼1. According to theoretical and experimental studies, the exponent α is given by 2/(2+p) where the charge-phonon scattering rate 1/τph is proportional to T ^p . Therefore our results yield p ˜ 0, suggesting that there is little Dirac fermion-phonon scattering, a great advantage for applications in nanoelectronics.