Stochastic resonance in a single-well anharmonic oscillator with coexisting attractors

• We report stochastic resonance in a single-well anharmonic oscillator.
• Resonance occurs due to noise-induced switching between coexisting orbits.
• We analyse the variation of measures of stochastic resonance with a control parameter.

We present a numerical investigation of occurrence of stochastic resonance in a single-well anharmonic oscillator where period doubling and chaotic orbits coexist with a large amplitude periodic orbit for a wide range of values of frequency ω   of the external periodic force fsinωt. Stochastic resonance occurs due to the noise-induced switching between the large amplitude periodic orbit and another coexisting orbit. The signal-to-noise ratio (SNR)(SNR) is found to be maximum at an optimum value of noise intensity (DMAXDMAX) and with ω,DMAXω,DMAX increases while SNRSNR at DMAXDMAX decreases linearly in different rates with respect to the coexisting chaotic and periodic attractors. The mean residence times around the two coexisting orbits are not same at D=DMAXD=DMAX.