The crucial role of temperature in atomic scale friction

Abstract

The temperature dependence of atomic scale friction is analyzed theoretically, in the framework of a two-spring–two-mass generalization of the Prandtl–Tomlinson model, taking into account an ultra-low value of the effective mass of the contact. A decrease of the friction force with increasing temperature is predicted, that is unexpectedly strong, nontrivial in detail, and accompanied by transitions between different regimes of sliding corresponding to different scenarios of energy dissipation. The results indicate a much more pronounced role of thermally driven dynamics in friction than has ever been imagined, and they should strongly stimulate temperature-variable friction force microscopy experimentation.