Room Temperature Non-equilibrium Bose-Einstein Condensation of Dirac Polaritons in WS₂ Monolayer

Exciton–polariton Bose Einstein condensation (BEC) in atomic monolayers promises nonlinear and reconfigurable quantum photonic platforms operating at ambient conditions. Yet it has remained elusive beyond cryogenic and weakly nonlinear microcavities. Here we demonstrate room-temperature (RT) non-equilibrium polariton condensation in a monolayer of tungsten disulfide (WS₂), enabled by topological light confinement through a bound state in the continuum (BIC) arising from interfering Dirac modes. Strong coupling is confirmed by a ~60 meV Rabi splitting persisting across the lasing threshold. The BIC-imprinted polarization texture transfers to the polariton superfluid, carrying a topological charge of |2|. The BIC dispersion supports omnidirectional negative-mass polaritons that self-trap via a reservoir-induced potential. Above threshold, discrete condensate levels emerge in the Dirac gap and undergo pump-driven blueshifts up to ~28 meV. The evolving loss landscape and a space-variant self-trapping potential enable dynamic spectral control. This RT open-cavity platform supports condensate arrays and integration with van der Waals heterostructures and Moiré superlattices, tracing a pathway toward emerging functionalities.