Macroscopic coherence and vorticity in room-temperature polariton condensate confined in a self-assembled perovskite microcavity
Exciton-polariton Bose-Einstein condensation at room temperature offers a promising pathway toward quantum photonic technologies that can operate under ambient conditions. A key challenge in this field is to engineer a controlled platform where strong confinement, nonlinear interactions, and structural disorder coexist, unlocking access to rich collective behavior and unconventional condensate dynamics. We demonstrate polariton condensation in CsPbBr$_3$ microplatelets that self-assemble into whispering gallery mode microresonators featuring tight lateral photon confinement finely balanced with intrinsic disorder. The system exhibits hallmark signatures of out-of-equilibrium condensation, including a non-linear increase in emission intensity, spectral narrowing, and interaction-induced blueshift. Intrinsic disorder subtly reshapes the cavity energy landscape, inducing condensate fragmentation and enabling direct optical access to the condensate wavefunction. Interferometric measurements reveal extended phase coherence, whereas characteristic fork-shaped fringe dislocations confirm the presence of quantized vortices pinned by the disordered potential. These topological excitations underscore the rich physics driven by the interplay of gain, loss, confinement, and disorder. Our work establishes a scalable platform for investigating driven-dissipative quantum fluids of light at room temperature, where the intrinsic disorder balances optical confinement and provides a window into condensate wavefunction, coherence, and vortex phenomena. This study system opens new opportunities for exploring many-body physics and potentially advancing topological photonics in integrable microcavity architectures.