  Controlling light-matter interactions in solid-state systems has motivated
intense research to produce bosonic quasi-particles known as
exciton-polaritons, which requires strong coupling between excitons and cavity
photons. Ultra-low threshold coherent light emitters can be achieved through
lasing from exciton-polariton condensates, but this generally requires
sophisticated device structures and cryogenic temperatures. Polaritonic
nanolasers operating at room temperature lie on the crucial path of related
research, not only for the exploration of polariton physics at the nanoscale
but also for potential applications in quantum information systems, all-optical
logic gates, and ultra-low threshold lasers. However, at present, progress
toward room-temperature polariton nanolasers has been limited by the thermal
instability of excitons and the inherently low quality factors of nanocavities.
Here, we demonstrate room-temperature polaritonic nanolasers by designing
wide-gap semiconductor heterostructure nanocavities to produce thermally stable
excitons coupled with nanocavity photons. The resulting mixed states of
exciton-polaritons with Rabi frequencies of approximately 370 meV enable
persistent polariton lasing up to room temperature, facilitating the
realization of miniaturized and integrated polariton systems.
