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

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 f sin ω t . 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 ) is found to be maximum at an optimum value of noise intensity ( D MAX ) and with ω , D MAX increases while SNR at D MAX 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 = D MAX .