EXTRACTING ENERGY FROM NOISE: NOISE BENEFITS IN HYSTERETIC SYSTEMS

Abstract

Noise plays a major role in the behavior of various physical and biological systems, its effects being increasingly pronounced with decrease in system size. While it is jeopardizing the future development of several nanotechnologies, such as magnetic data storage, noise can also play a constructive role in many nonlinear systems, activating a resonance response. In this paper, it is proven that various hysteretic systems can exhibit such coherent behavior — a phenomenon that is generally known as coherence resonance when is solely induced by noise, and stochastic resonance when an external oscillatory signal is present. The quantity used to characterize the regularity of the stochastic output is the power spectrum, which displays a maximum at the resonance frequency. The calculation of the spectral densities for the outputs of hysteretic systems is performed in the framework of stochastic processes defined on graphs. The case of hysteretic systems described by rectangular loops is discussed and analytical expressions for the output power spectra are derived. These theoretical results suggest that hysteretic systems can be used by nanotechnology for concentrating the energy of a flat, noisy input into a short bandwidth frequency region.