KINETIC ISING-SYSTEM IN AN OSCILLATING EXTERNAL-FIELD - STOCHASTIC RESONANCE AND RESIDENCE-TIME DISTRIBUTIONS

Experimental, analytical, and numerical results suggest that the mecha nism by which a uniaxial single-domain ferromagnet switches after sudd en field reversal depends on the field magnitude and the system size. Here we report new results on how these distinct decay mechanisms infl uence hysteresis in a two-dimensional nearest-neighbor kinetic Ising m odel. We present theoretical predictions supported by numerical simula tions for the frequency dependence of the probability distributions fo r the hysteresis-loop area and the period-averaged magnetization, and for the residence-time distributions. The latter suggest evidence of s tochastic resonance for small systems in moderately weak oscillating f ields. (C) 1997 American Institute of Physics.