Bistability and hysteresis in the sliding friction of a dimer

The sliding friction of a dimer moving over a periodic substrate and subjected to an external force is studied in the steady state for arbitrary temperatures within a one-dimensional model. Nonlinear phenomena that emerge include dynamic bistability and hysteresis, and can be related to earlier observations for extended systems such as the Frenkel-Kontorova model. Several observed features can be satisfactorily explained in terms of the resonance of a driven-damped nonlinear oscillator. Increasing temperature tends to lower the resonant peak and wash out the hysteresis.