HIGH-FREQUENCY STOCHASTIC RESONANCE IN SQUIDS

It is shown theoretically and by analogue electronic experiment that s tochastic resonance (SR), in which a weak periodic signal can be optim ally enhanced by the addition of noise of appropriate intensity, is to be anticipated in underdamped SQUIDs (superconducting quantum interfe rence devices). It manifests under conditions quite unlike those neede d for classical SR, which is restricted to low frequencies and confine d to systems that are both overdamped and bistable. The zero-dispersio n SR reported here can be expected over a vastly wider, tunable, range of high frequencies in highly underdamped SQUIDs that need not necess arily be bistable.