Long-range order in a high-density electron-hole system at room temperature during superradiant phase transition

The authors have experimentally investigated the formation of off-diagonal long-range order and non-equilibrium BEC-like condensation in GaAs/AlGaAs heterostructures during superradiant (SR) emission at room temperature. The conclusive evidence of the establishment of phase coherence over a macroscopic range during the superradiant quantum phase transition is reported. The first-order spatial correlation function of the e-h system is determined by evaluating interference patterns of SR emission using Young's double slit.