Stochastic Resonance and Brownian Machinery: New Results — New Applications - New Goals

Abstract

Is it possible to extract energy from random fluctuations and put it to beneficial use? This challenging question has provoked discussions ever since the early days of Brownian motion studies. Generally, noise in dynamical systems is considered a nuisance. But in certain nonlinear systems the presence of noise can in fact enhance the detection of weak signals. This phenomenon, called Stochastic Resonance (SR) does find useful applications in physical, technological and biomedical contexts [1]. In a second class of systems that are periodic - but which lack reflection symmetry - directed, noise induced transport can take place. The directed motion of particles in periodic potentials requires at least one source of non-equilibrium which must inherit an explicit or inherent statistical asymmetry. Such non-equilibrium systems have become known in the literature under the label of “ratchets” [2]. In both situations the importance of fluctuations is elevated to a level where noise must be viewed as source of order and complexity in its own right.