Characteristics of Stochastic Resonance in Asymmetric Duffing oscillator

We study the characteristics of stochastic resonance (SR) in the Duffing oscillator with three types of asymmetries in its double-well potential. The asymmetries controlled by a parameter α are introduced in the potential by varying (i) the depth of the left-well alone, (ii) the location of the minimum of the left-well alone and (iii) both depth and location of the minimum of the left-well alone. The characteristics of SR in the asymmetric cases are different from the symmetric case (α = 1). We find that asymmetry has a strong influence on the optimum noise intensity at which signal-to-noise ratio (SNR) is maximum, mean residence time at resonance and the probability distribution of residence time in the leftand right-wells. For a range of values of α, α = 1, SNR is found to be relatively higher than for α = 1.