Stochastic Resonance in Washboard Potentials

We study the mobility of an overdamped particle in a periodic potential tilted by a constant force. The mobility exhibits a stochastic resonance in inhomogeneous systems with space dependent friction coefficient. The result indicates that the presence of oscillating external field is not essential for the observability of stochastic resonance, at least in the inhomogenous medium.Comment: 10 pages, 3 figure