CHIAO-HSUAN WANGGullans M.JPorto J.VPhillips W.DTaylor J.M.2022-11-112022-11-11201924699926https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063253624&doi=10.1103%2fPhysRevA.99.031801&partnerID=40&md5=02837fbbc771cd5784136f281fe8987ehttps://scholars.lib.ntu.edu.tw/handle/123456789/624596A 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 lack of a particle number conservation. We recently described a photon thermalization mechanism which gives rise to a grand canonical ensemble of light with effective photon number conservation between a subsystem and a particle reservoir. This mechanism occurs during Doppler laser cooling of atoms where the atoms serve as a temperature reservoir while the cooling laser photons serve as a particle reservoir. In contrast to typical discussions of BEC, our system is better treated with a controlled chemical potential rather than a controlled particle number, and is subject to energy-dependent loss. Here, we address the question of the possibility of a BEC of photons in this laser cooling photon thermalization scenario and theoretically demonstrate that a Bose condensation of photons can be realized by cooling an ensemble of two-level atoms (realizable with alkaline-earth atoms) inside a Fabry-Pérot cavity. © 2019 American Physical Society.Alkalinity; Atoms; Bose-Einstein condensation; Condensation; Conservation; Excitons; Laser cooling; Laser theory; Light; Photons; Statistical mechanics; Alkaline-earth atoms; Bose condensation; Bose-Einstein condensates; Energy dependent; Grand canonical ensemble; Laser cooling of atoms; Low temperatures; Temperature reservoirs; Atom lasersjournal article10.1103/PhysRevA.99.0318012-s2.0-85063253624