Stochastic resonance and signal recovery in two-dimensional arrays of coupled oscillators

In this article, some prominent phenomena in a two-dimensional square array of coupled nonlinear oscillators driven by a periodic signal plus white noise are presented: (i) For a subthreshold periodic signal (A⩽1-b), besides conventional stochastic resonance (SR) as a best cooperative result of noise and periodic forcing, there also exists spontaneous SR induced purely by noise itself. The effects of these two SR phenomena are shown to be much better than those in the uncoupled case. (ii) For a superthreshold periodic driving (A>1-b), a certain amount of noise cannot only recover the concealed deterministic signal at the input frequency, but also significantly enhance the recovered signal to several times higher via the happening of SR. This phenomenon of SR is shown to be impossible in a single oscillator system.