Leaky exciton condensates in transition metal dichalcogenide moiré bilayers

We show that the "dark condensates" arise when excitons form a Bose-Einstein condensate in material with an indirect bandgap are not completely dark to optical emission. Rather, such states "leaky which emission is facilitated by many-body interactions. analyze properties of these leaky condensates context twisted bilayers transition metal dichalcogenides, host strongly interacting and bandgap. this interaction-driven "leaky" dominates photoluminescence at low temperatures, distinctive qualitative features. Finally, we propose materials, unique intervalley physics can lead crystal symmetry-breaking excitonic ordering, implications for processes.