Bose Condensation of Photons Thermalized via Laser Cooling of Atoms
Chiao Wang, Michael Gullans, James V. Porto, William D. Phillips, Jacob Taylor
A Bose-Einstein condensate (BEC) is a quantum phase of matter achieved at low temperatures.Photons, one of the most prominent species of bosons, do not typically condense due to the lackof a particle number-conservation. We recently described a photon thermalization mechanismwhich gives rise to a grand canonical ensemble of light with effective photon number conser-vation between a subsystem and a particle reservoir. This mechanism occurs during Dopplerlaser cooling of atoms where the atoms serve as a temperature reservoir while the cooling laserphotons serve as a particle reservoir. Here we address the question of the possibility of a BECof photons in this laser cooling photon thermalization scenario and theoretically demonstratethat a Bose condensation of photons can be realized by cooling an ensemble of two-level atoms(realizable with alkaline earth atoms) inside a Fabry- Perot cavity.