Hybrid Photonic-Plasmonic Cavities Based on the Nanoparticle-on-a-Mirror Configuration for Large Purcell Factors at Visible Wavelengths

Hybrid plasmonic-photonic cavities are promising structures for enhancing the emission of quantum emitters by increasing the Purcell factor. In this work, we investigate a novel hybrid structure with a nanoparticle-on-a-mirror configuration coupled to a dielectric photonic crystal. This configuration allows to obtain small mode volumes due to the metallic nanoparticle and large Q-factors due to the photonic crystal. We report Purcell factors larger than $10^{5}$ in the visible spectral region, which are achieved with structures that are experimentally feasible with current technology. We expect that our results may open new avenues for boosting light-matter interactions in nanophotonic systems.