Volume 87, Number 5, September 2009
Article Number 50003
Number of page(s) 6
Section General
Published online 18 September 2009
EPL, 87 (2009) 50003
DOI: 10.1209/0295-5075/87/50003

Double entropic stochastic resonance

P. S. Burada1, G. Schmid1, D. Reguera2, J. M. Rubi2 and P. Hänggi1

1   Institut für Physik, Universität Augsburg - Universitätsstr. 1, D-86135 Augsburg, Germany
2   Departament de Física Fonamental, Facultat de Física, Universidad de Barcelona Martí i Franqués 1, E-08028 Barcelona, Spain

received 6 July 2009; accepted in final form 19 August 2009; published September 2009
published online 18 September 2009

We demonstrate the appearance of a purely entropic stochastic resonance (ESR) occurring in a geometrically confined system, where the irregular boundaries cause entropic barriers. The interplay between a periodic input signal, a constant bias and intrinsic thermal noise leads to a resonant ESR phenomenon in which feeble signals become amplified. This new phenomenon is characterized by the presence of two peaks in the spectral amplification at corresponding optimal values of the noise strength. The main peak is associated with the manifest stochastic resonance synchronization mechanism involving the inter-well noise-activated dynamics while a second peak relates to a regime of optimal sensitivity for intra-well dynamics. The nature of ESR, occurring when the origin of the barrier is entropic rather than energetic, offers new perspectives for novel investigations and potential applications. ESR by itself presents yet another case where one constructively can harvest noise in driven nonequilibrium systems.

02.50.Ey - Stochastic processes.
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
05.10.Gg - Stochastic analysis methods (Fokker-Planck, Langevin, etc.).

© EPLA 2009