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.
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