Eur. Phys. J. D 62, 103-108 (2011)
https://doi.org/10.1140/epjd/e2010-00269-2

Stochastic resonance between counterpropagating Bloch walls

A nonequilibrium-potential description in a neighborhood of the nonequilibrium Ising-Bloch bifurcation

¹ Instituto de Investigaciones Físicas de Mar del Plata (IFIMAR, Univ. Nac. de Mar del Plata and CONICET), Deán Funes 3350, B7602 AYL Mar del Plata, Argentina
² Instituto de Física de Cantabria (UC and CSIC), Avda. de los Castros, s/n, 39005 Santander, Spain

^a e-mail: deza@mdp.edu.ar

Received: 15 May 2010
Received in final form: 16 August 2010
Published online: 10 November 2010

Abstract

The nonequilibrium Ising-Bloch front bifurcation of the FitzHugh-Nagumo model with nondiffusing inhibitor provides a beautiful instance of an extended bistable system made up of propagating (Bloch) fronts. Moreover, these fronts are chiral and parity-related, and the barrier between them is nonetheless but a stationary Ising front. By means of numerical simulation in the neighborhood of this bifurcation, we demonstrate the existence of stochastic resonance in the transition between Bloch fronts of opposite chiralities, when an additive noise is included. The signal-to-noise ratio is numerically observed to scale with the distance to the critical point. This scaling law is theoretically characterized in terms of an effective nonequilibrium potential.