  We theoretically describe the stationary regime and coherent dynamics of a
capacitively shunted transmon-type qubit which is placed in front of a mirror.
The considered qubit is irradiated by two signals: pump (dressing) and probe.
By changing amplitudes and frequencies of these signals we study the system
behaviour. The main tool of our theoretical analysis is solving of the Lindblad
equation. We also consider Lindblad superoperators in charge and energy bases
and compare the results. Theoretically obtained occupation probability is
related to the experimentally measured value. This study helps to understand
better the properties of qubit-mirror system and gives new insights about the
underlying physical processes.
