Modulation of two-photon processes in monolayer TMDs

In transition metal dichalcogenides (TMDs), a two-dimensional material, photoexcited carriers naturally thermalize and relax to the neutral 1s excitonic ground state. There also exist p-like states, which are deemed "dark," but can be accessed through two-photon processes. We gain insight into the nature of these p-like states by approximating the local potential environment with Rytova-Keldish potentials. Once excited, these states can relax to "bright" states which can be optically observed. In optical measurements at cryogenic temperatures, we see how the excitation into these states is influenced by the addition of radio frequency (RF) fields and couple to plasmonic antennae. These processes can also be enhanced by coupling with optical cavity modes. Our results point to possible applications in sensing and optical quantum computing networks.