Stochastic resonance in three discrete states

A stochastic resonator constructed of three discrete states is proposed to explain microscopically why one applies the Arrhenius-type relaxation time to the time scale of thermal relaxation of each two-state kinetic Ising spin in previous papers which have studied stochastic resonance using Ising spins. The interaction or array enhancement effect in stochastic resonance is shown not to appear in an ensemble of Ising spins with identical interaction and without Arrhenius-type relaxation time, while even two coupled Ising spins without Arrhenius-type relaxation time show stochastic resonance. Moreover, coupled resonators show stochastic resonance which is enhanced around some appropriate coupling strength.