Observation of the emergent photon in a metastable fractionalized phase of Bose-condensed excitons: Monte Carlo simulation

Using the Monte Carlo simulation, we studied fractionalized phases in a model of exciton Bose condensate and found evidence for an emergent photon in a finite size system. The fractionalized phase is a metastable Coulomb phase where an emergent photon arises as a gapless collective excitation of the excitons. We also studied a possibility of the fractionalized spiral (spiral*) phase where fractionalization and long range spiral order of the exciton condensate coexist.