Strong coupling of single quantum dots with low-refractive-index/high-refractive-index materials at room temperature

Strong coupling between a cavity and transition dipole moments in emitters leads to vacuum Rabi splitting. Researchers have not reported strong coupling between a single emitter and a dielectric cavity at room temperature until now. In this study, we investigated the photoluminescence (PL) spectra of colloidal quantum dots on the surface of a SiO₂/Si material at various collection angles at room temperature. We measured the corresponding reflection spectra for the SiO₂/Si material and compared them with the PL spectra. We observed PL spectral splitting and regarded it as strong coupling between colloidal quantum dots and the SiO₂/Si material. Upper polaritons and lower polaritons exhibited anticrossing behavior. We observed Rabi splitting from single-photon emission in the dielectric cavity at room temperature. Through analysis, we attributed the Rabi splitting to strong coupling between quantum dots and bound states in the continuum in the low-refractive-index/high-refractive-index hybrid material.