The dual stochastic response of nonlinear systems

Laboratoire d'Electronique Quantique-Physique des Lasers, UMR CNRS PALMS 6627 Université de Rennes 1 - Campus de Beaulieu, F-35042 Rennes Cedex, France

Received: 2 August 2004
Accepted: 22 October 2004

Abstract

Noise plays a key role in the dynamics of many nonlinear systems through the concept of stochastic resonance. We demonstrate that, when a single noise is applied to two functions with opposite parities, the behavior of a nonlinear system is governed by a dual stochastic response that, compared to the usual stochastic resonance, leads to a broad-band forcing frequency range, a sensitivity increased by a factor of 20 and a robustness improved by a factor of 40. The wide applicability of such a response is supported by our experimental observations in optics and in electronics, and may also be important in many other nonlinear systems embedded in noise, as for instance the Earth's climate.