Phase transitions in a system of atoms interacting with a coherent field

Igor Yu. Chestnov, A. P. Alodjants, Sergei M Arakelyan

The problem of photon phase transition in a system of two-level atoms interacting with a quantized single-mode electromagnetic field in the presence of optical collisions is discussed. The photon field is shown to undergo a high-temperature second order phase transition into the coherent (superradiant) state at large negative values of atom-field detuning and under the condition of thermalization of coupled atom-light states.

Ju Wang

The evolution law of the system which consists of coherent-atoms interacting with coherent-cavity-field is shown by using evolutional factor.The process of interaction in the system is studied.It is found that the quantum information can be transfer not only between cavities and atoms but also different sets of cavities.Furthermore,the conditions of information exchange are usually related to the atoms transition frequency(ωa,k) and its relative phase(ξ),the light-field frequency(ωf,k) and its relative phase(η),the coupled intensity between atom and light-field(g),as well as the interaction time(t).But it is only related to g and t under the resonance interaction atoms with light-field.

Almas F. Sadreev, A. P. Slivinskiǐ

A. P. Alodjants, Igor Yu. Chestnov, Sergei M Arakelyan

The problem of photonic phase transition for the system of a two-level atomic ensemble interacting with a quantized single-mode electromagnetic field in the presence of optical collisions (OCs) is considered. We have shown that for large and negative atom-field detuning a photonic field exhibits high-temperature second-order phase transition to superradiant state under thermalization condition for coupled atom-light states. Such a transition can be connected with superfluid (coherent) properties of photonlike low branch (LB) polaritons. We discuss the application of metallic cylindrical waveguide for observing predicted effects.