Stochastic multiresonance in a chaotic map with fractal basins of attraction - art. no. 026215

Noise-free stochastic resonance in a chaotic kicked spin model at the edge of the attractor merging crisis is considered. The output signal reflects t he occurrence of crisis-induced jumps between the two parts of the attracto r. As the control parameter-the amplitude of the magnetic field pulses-is v aried, the signal-to-noise ratio shows plateaus and multiple maxima, thus s tochastic multilesonance is observed. It is shown that the multiresonance o ccurs due to a fractal structure of the precritical attractors and their ba sins. In the adiabatic approximation theoretical expression for the signal- to-noise ratio is derived, based on the theory of oscillations in average c risis-induced transient lifetimes. Numerical and theoretical results agree quantitatively just above the threshold for crisis and qualitatively in a w ide range of the control parameter.