Resonance-like phenomenon of mobility in 2D overdamped washboard potential

The transport of an overdamped Brownian particle in a two-dimensional (2D) coupled periodic potential titled by a constant force is considered. The mo bility velocity of the particle as a function of the temperature is investi gated. The simulated results show that the stochastic resonance (SR) can be observed when the diffusion channel is narrower at the minima than that at the saddle points of the potential. A one-dimensional effective potential is also proposed in order to understand qualitatively the occurrence of SR. (C) 2000 Elsevier Science B.V. All rights reserved.