The potential distribution (units in meV) when a top graphite flake is moved. The potential distribution (units in meV) when a top graphite flake is moved relative to the bottom graphite flake of the same size (11a versus 6a in the × and y axis, respectively, where a = 0.142 nm) in the xy plane. The movement values are in terms of a. As movement should tend towards highest negative potential, the general landscape indicates a general tendency for the top flake to retract. However, the undulations imbue a possibility for it not to return to the exact original position and orientation.
Ng et al. Nanoscale Research Letters 2012 7:185 doi:10.1186/1556-276X-7-185