Superradiant quantum phase transition in a semiconductor at room temperature: myth or reality?

The conditions and mechanism of occurrence of the nonequilibrium superradiant phase transition in a bulk semiconductor in the strong coupling regime at room temperature are considered. An analysis of experimental data is carried out and the characteristic properties of this phase transition are compared with previously studied quantum phase transitions in ultracold gases in traps, in a set of quantum dots, superconducting qubits and others. It has been demonstrated that all the basic properties of the previously discovered collective state, formed during the process of induced condensation of electron-hole pairs at room temperature, correspond to those of the superradiant phase transition observed in other media.