Condensation of cavityexciton-polaritons in perovskite nanocrystals at room-temperature

Strong lightmatter coupling and excitonpolariton condensates oer a promising approach to introduce robust interactions and nonlinear eects into a wide array of photonic technologies, spanning from high-speed all-optical logic to low-threshold topological lasers. By integrating colloidal semiconductor quantum dotsnotable for their pronounced three-dimensional connement and excellent optical characteristicsas active medium in microcavities, it is possible to boost polaritonic interactions through quantum connement. Nonetheless, the realization of excitonpolariton condensation in microcavities at room temperature has remained elusive for both epitaxial and colloidal quantum dots. In this work [1], we demonstrate room-temperature polariton condensation by embedding a thin lm of monodisperse colloidal CsPbBr3 quantum dots within a tunable optical resonator. This resonator incorporates a Gaussian-shaped deformation creating a wavelength-scale potential well for polaritons. Under pulsed optical excitation, we demonstrated the emergence of polariton condensation manifested by a superlinear increase in emission intensity, a narrowing of the emission linewidth, a blueshift (Fig. 1a), and an extension of temporal coherence (Fig. 1b). Our results highlight the potential of perovskite-based colloidal quantum dots, celebrated for their remarkable optical properties and high tunability, as a cutting-edge platform for next-generation polaritonic devices.