  We study the thermal effects on the frictional properties of atomically thin
sheets. We simulate a simple model based on the Prandtl-Tomlinson model that
reproduces the layer dependence of friction and strengthening effects seen in
AFM experiments. We investigate sliding at constant speed as well as reversing
direction. We also investigate contact aging: the changes that occur to the
contact when the sliding stops completely. We compare the numerical results to
analytical calculations based on Kramers rates. We find that there is a slower
than exponential contact aging that weakens the contact and that we expect will
be observable in experiments. We discuss the implications for sliding as well
as aging experiments.
