On the combined influence of a stochastic field and a heat bath on the transfer phenomena in a two-level system

Utilizing a master equation which includes an additional stochastic averaging we study the combined action of a stochastic field and a heat bath on the kinetic processes in a quantum system. The approach is applied to derive the rate constants and steady-state populations for a two-level system. It can be demonstrated that the ratio between the backward and forward transition rates as well as between the steady-state populations may change in a wide range. The transition from the Boltzmann ratio to a ratio equal 1 is discussed in detail in its dependence on the various parameters involved.