The quantum confinement inatomically-thin transition metal dichalcogenides (TMDCs) has been investigatedfor single photon emission based on naturally or artificially occurringdefects. In particular, the precise control of the position of a single photonemitter by applying mechanical strains to the TMDC is feasible. Strains havebeen induced in TMDCs using various nanostructures including dielectricpillars, nanobubbles, optical waveguide, metal nanogaps, and metalnanoparticles. However, polarization control and integration with ahigh-quality (Q) cavity to increase the Purcell factor remain elusive inTMDC-based single photon sources.
In this talk, I will presentthe deterministic control of both the position and polarization of singlephoton emitters in atomically thin WSe2 placed on a nanogap array. Manipulationof the band structure by a local strain gradient generates a potential well atthe nanogap site, and position-controlled single photon emission issubsequently achieved. Additionally, directional elongations of the potentialwell, which are tuned by changing the nanogap size, allowpolarization-controlled single photon emission. Moreover, single photons with ag(2) of ~0.1 are generated at 4-20 K. To take a full advantage of suchdeterministic control of the position and polarization of single photonemitters, the emitters are integrated with one-dimensional photonic crystalcavities. Therefore, this approach is a unique way to develop next-generation,deterministic, controllable single photon emitters based on TMDC materials,which outperform the present single photon sources with random occurrence anduncontrolled polarization properties.