GIANT NONLINEARITY IN THE LOW-FREQUENCY RESPONSE OF A FLUCTUATING BISTABLE SYSTEM

The response of a bistable system to a low-frequency driving force is demonstrated to display a giant nonlinearity: a sinusoidal force can i nduce a nearly rectangular signal in the system even when its amplitud e is small. The nonlinearity comes about through the force modulating the effective activation energies of fluctuational transitions between the stable states, which in turn can give rise to strong modulation o f the transition probabilities and the populations of the states, for low noise intensities. Theoretical results are shown to be in good agr eement with the results of analog and digital simulations.