ATOMIC DIPOLE DYNAMICS IN THE THERMAL QUANTIZED CAVITY FIELD

We consider the resonant interaction of a two-level atom with a therma l state of the quantized field in a lossless cavity. Non-trivial dynam ics of the atomic dipole moment and the field quadrature components ar ise if the atom is initially prepared in a coherent superposition of i ts upper and lower state. In particular, the initial thermal field sta te acquires a well defined phase that corresponds to the initial phase of the superposition atomic state. Population trapping occurs when th e intensity grows.