Room-temperature Strong Coupling of Au Nanorod-WSe2 Heterostructures

All-solid-state strong light-matter coupling systems with large vacuum Rabi splitting are great important for quantum information application, such as quantum manipulation, quantum information storage and processing. The monolayer transition metal dichalcogenides (TMDs) have been explored as excellent candidates for the strong light-matter interaction, due to their extraordinary exciton binding energies and remarkable optical properties. Here, for both of experimental and theoretical aspects, we explored resonance coupling effect between exciton and plasmonic nanocavity in heterostructures consisting of monolayer tungsten diselenide (WSe2) and an individual Au nanorod. We also study the influences on the resonance coupling of various parameters, including localized surface plasmon resonances of Au nanorods with varied topological aspects, separation between Au nanorod and monolayer WSe2 surface, and the thickness of WSe2. More importantly, the resonance coupling can approach the strong coupling regime at roomtemperature by selecting appropriate parameters, where an anti-crossing behavior with the vacuum Rabi splitting strength of 98 meV was observed on the energy diagram.