Charge oscillations in two-level system in the presence of time-dependent coupling with electron reservoir

We consider a two-level system coupled with a free-electron reservoir (ER) and exposed to the influence of the electromagnetic field. Applying the equation of motion method for appropriate correlation functions the electron dynamics (the charge oscillations between two levels of a system) has been investigated theoretically for different kinds of coupling with the ER. It is shown, that the damping of charge oscillations depends largely on the time of interaction with the ER. These oscillations depend also on the amplitude and frequency of time-dependent energy levels and form of coupling with the ER.