Lasing and BEC of microcavity polaritons at elevated temperatures

We investigate the room temperature polaritons dynamics of wide bandgap semiconductor microcavities. Our efforts are focused on microcavities based on wide bandgap semiconductors, such as GaN and ZnO, which possess large exciton binding energies and consequently exhibit enormous Rabi splittings, ensuring the thermal stability of excitons even at room temperature. In this context, the strong coupling regime is indeed observed for the first time in a hybrid bulk GaN microcavity at room temperature. The polaritonic properties are studied with a range of spectroscopic techniques and reveal the occurrence of a polaritonic lasing transition, characterized by an ultralow threshold. The condensate originated emission exhibits a stochastic change of its polarization state. This result is regarded as evidence of spontaneous symmetry breaking. Our observations thus indicate the realization of the first polaritonic Bose-Einstein condensate at room temperature.EThOS - Electronic Theses Online ServiceGBUnited Kingdo