Issue
EPL
Volume 77, Number 5, March 2007
Article Number 50004
Number of page(s) 5
Section General
DOI http://dx.doi.org/10.1209/0295-5075/77/50004
Published online 19 February 2007
EPL, 77 (2007) 50004
DOI: 10.1209/0295-5075/77/50004

Stochastic resonance with weak monochromatic driving: Gains above unity induced by high-frequency signals

J. Casado-Pascual1, D. Cubero1 and J. P. Baltanás2

1  Física Teórica, Universidad de Sevilla - Apartado de Correos 1065, Sevilla 41080, Spain
2  Departamento de Física Aplicada II, Universidad de Sevilla - Avda. Reina Mercedes, 2, Sevilla 41012, Spain


received 30 October 2006; accepted in final form 5 January 2007; published March 2007
published online 19 February 2007

Abstract
We study the effects of a high-frequency (HF) signal on the response of a noisy bistable system to a low-frequency subthreshold sinusoidal signal. We show that, by conveniently choosing the ratio of the amplitude of the HF signal to its frequency, stochastic resonance gains greater than unity can be measured at the low-frequency value. Thus, the addition of the HF signal can entail an improvement in the detection of weak monochromatic signals. The results are explained in terms of an effective model and illustrated by means of numerical simulations.

PACS
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
05.10.Gg - Stochastic analysis methods (Fokker-Planck, Langevin, etc.).
02.50.-r - Probability theory, stochastic processes, and statistics.

© Europhysics Letters Association 2007