General theory of Bose-Einstein condensation applied to an ideal quantum gas of photons in an optical microcavity
Eberhard E. Müller
This paper provides, first, a succinct theoretical derivation of Bose-Einstein condensation in a grand-canonical ideal photon gas elaborating on previous results [M\"uller, Ann. Phys. 184, 219 (1988); Physica A (Amsterdam, Neth.) 139, 165 (1986)] additionally including new results on the condensate function and, second, applies this framework to consistently explain experimental findings on Bose-Einstein condensation of photons in an optical microcavity [Klaers, Schmitt, Vewinger, and Weitz, Nature 468, 545 (2010)]. A grand-canonical photon gas is realized by a steady state of a photon flux deviating from a canonical thermodynamic Planck equilibrium. The theoretical approach presented here invites to significantly widen the experimental framework for Bose-Einstein condensation of photons including three-dimensional photon resonators and thermalization mechanisms different from a dye medium in the cavity.
arXiv:1801.05220•Physical Review A•Nov 18, 2019•2 citations