Non-Dynamical Stochastic Resonance: Theory and Experiments with White and Arbitrarily Coloured Noise

We describe the simplest system which shows stochastic resonance. Theoretical results for white and (almost) arbitrarily coloured noise are presented. The new system has new, unique properties which originate from its non-dynamical character; for example, the strength and phase shift of periodic response of the system is independent of the frequency. Experiments have been carried out with the following noise processes: (physical) white noise, (physical) Lorentzian noise and (physical) 1/ f noise. With a small extension of the system, its linear-response regime can be significantly increased. As the system is similar to some simple models of neurons, the new results might have not only physical but also biological importance.