Stochastic resonance in a non-smooth system under colored noise excitations with a controllable parameter.

Stochastic resonance is studied in a class of non-smooth systems with a controllable parameter causing a change among monostability, bistability, and multistability, driven by colored noise. The system becomes smooth at a bifurcation point. Time scales in the non-smooth well are analyzed and transition rates of the non-smooth potential barriers are obtained. Analytical expressions for the response amplitude depending on the controllable parameter, frequency, noise intensity, and correlation time are derived in the bistable and multistable regions in the adiabatic limit. With the decrease of frequency, the optimal correlation time according to the maximum response is increasing; on the contrary, the optimal noise intensity is on the decline. Multistability of the system enhances the optimal transition rates and optimal response amplitude.