of Photonlike Atom-Light Polaritons

S. Portolan, Salvatore Savasta

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

We propose a method for obtaining a Bose-Einstein condensate of an ideal one-dimensional gas of atom-light polaritons of the lower branch in a trap at high temperatures (on the order of room temperature or higher). The system under consideration is an atomic ensemble that interacts with a single-mode quantum electromagnetic field in the presence of optical collisions with a high-pressure buffer gas. The possibility of using biconical waveguides for revealing the predicted phenomenon is discussed. The dynamics of the polariton condensate in the trap is investigated on the basis of the variational approach.

Joonhyuk Kwon, Youngshin Kim, Alfonso Lanuza +1 more

Igor Yu. Chestnov, A. P. Alodjants, Sergei M Arakelyan +3 more

We study the problem of high-temperature Bose-Einstein condensation (BEC) of atom-light polaritons in a waveguide cavity appearing due to the interaction of two-level atoms with (nonresonant) quantized optical radiation in the strong-coupling regime and in the presence of optical collisions (OCs) with buffer-gas particles. Specifically, we propose a special biconical waveguide cavity (BWC), permitting localization and trapping of low-branch (LB) polaritons imposed by the variation of the waveguide radius in longitudinal direction. We have shown that the critical temperature of BEC occurring in the system can be high enough---a few hundred kelvins; it is connected with the photonlike character of LB polaritons and strongly depends on waveguide-cavity parameters. In the case of a linear trapping potential we obtain an Airy-shaped polariton condensate wave function which, when disturbed out of equilibrium, exhibits small-amplitude oscillations with the characteristic period in the picosecond domain.

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.

Dimitris G. Angelakis