Suppression of noise in nonlinear systems subjected to strong periodic driving.

An overdamped Brownian motion in "quartic" potential subjected to periodic driving has been considered. This system for the case of a weak periodic driving has been intensively studied during past decade within the context of stochastic resonance. It has been demonstrated that for the case of predominantly suprathreshold driving (the driving amplitude is significantly larger than the static threshold) the noise in the output signal is strongly suppressed at a certain frequency range: the signal-to-noise ratio demonstrates resonant behavior as a function of frequency.