Stochastic resonance in finite arrays of bistable elements with local coupling

TL;DR

This paper explores how finite arrays of coupled bistable systems exhibit enhanced stochastic resonance, with increased signal-to-noise ratio and gain, especially under multi-frequency driving, due to collective effects and nonlinear dynamics.

Contribution

It demonstrates that collective coupling in finite bistable arrays significantly enhances stochastic resonance, achieving gains above unity and revealing non-monotonic SNR behavior.

Findings

Enhanced SR in coupled arrays compared to single units

Gains larger than one for certain parameters and driving forces

Non-monotonic SNR dependence on coupling strength

Abstract

In this article, we investigate the stochastic resonance (SR) effect in a finite array of noisy bistable systems with nearest-neighbor coupling driven by a weak time-periodic driving force. The array is characterized by a collective variable. By means of numerical simulations, the signal-to-noise ratio (SNR) and the gain are estimated as functions of the noise and the interaction coupling strength. A strong enhancement of the SR phenomenon for this collective variable in comparison with SR in single unit bistable systems is observed. Gains larger than unity are obtained for some parameter values and multi- frequency driving forces, indicating that the system is operating in a non-linear regime albeit the smallness of the driving amplitude. The large SNR values observed are basically due to the fact that the output fluctuations are small and short lived, in comparison with their typical values in a linear regime. A non-monotonic behavior of the SNR with the coupling strength is also obtained.