▎ 摘　　要

The correlation between charge transport and mechanical deformation of the single layer graphene layer was studied with conductive probe atomic force microscopy/friction force microscopy in ultra-high vacuum. By measuring the current and friction on a graphene layer that is under mechanical stress, we identify crossover of two regimes in the current density that depend on the applied pressure. We suggest that the difference in work function under mechanical deformation as well as a change in the density of state and formation of a dipole field are responsible for this crossover behavior. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3609317]