The well-known problem of the phase transition in a two-level system coupled with the radiation field of a resonator is considered subject to the conduction electrons of the resonator walls. It is shown that the conduction electrons are important for consideration of the high-frequency...

A system of two-level atoms interacting with one mode of a quantized radiation field is considered by the quantum field theory. The existence of a phase transition to the spontaneous coherent state (SCS) is shown. This state arises from the Bose-Einstein condensation of the photons of the...

The dynamics of the Dicke-maser model is considered when the phase transition to a spontaneous coherent state takes place. In the molecular field approximation an expression for the atomic correlation function is found which shows dynamic peculiarities of the spontaneous coherent state (SCS) in...