Stochastic resonance in asymmetric bistable system driven by two different kinds of noise

The stochastic resonance (SR) in an asymmetric bistable system subject to multiplicative colored noise and additive white noise with a colored cross-correlation is investigated by two-state theory (TST) and unified colored noise approximation (UCNA). The analytic expression of the signal-to-noise (SNR) is obtained under adiabatic condition. The SNR is a non-monotonic function of intensities of multiplicative and additive noises, cross-correlation strength and time between noises and the correlation time of multiplicative noise, so SR appears in this bistable system. When the asymmetry of the bistable potential is not too large, it is more sensitive to control SR via adjusting the additive noise intensity than adjusting the multiplicative noise intensity. Moreover, when SNR gets as a function of the strength of coupling between multiplicative colored noise and additive white noise, double stochastic resonance (DSR) exhibits in the system.