Coupling Hexagonal Boron Nitride Quantum Emitters to Photonic Crystal Cavities.

Quantum photonics technologies require a scalable approach for the integration of nonclassical light sources with photonic resonators to achieve strong light confinement and enhancement of quantum light emission. Point defects from hexagonal boron nitride (hBN) are among the front runners for single photon sources due to their ultra-bright emission; however, the coupling of hBN defects to photonic crystal cavities has so far remained elusive. Here we demonstrate on-chip integration of hBN quantum emitters with photonic crystal cavities from silicon nitride (Si3N4) and achieve an experimentally measured quality factor (Q-factor) of 3300 for hBN/Si3N4 hybrid cavities. We observed 6-fold photoluminescence enhancement of an hBN single photon emission at room temperature. Our work will be useful for further development of cavity quantum electrodynamic experiments and on-chip integration of two-dimensional (2D) materials.