DYNAMICAL HYSTERESIS AND STOCHASTIC RESONANCE IN DRIVEN DISSIPATIVE QUANTUM 2-STATE SYSTEM

We study the dynamics of a periodically driven two-state system couple d to thermal environment. In the high temperature limit we have obtain ed analytic expressions for the average position of the particle and h ysteresis loop area. Both these quantities exhibit stochastic resonanc e behavior as a function of various parameters of the problem. These t wo resonances, however, occur at different values of the parameters. T he resonance condition obtained from the study of phase delay exhibits resonance at a fixed frequency independent of other physical paramete rs.