Engineering Quantum Nanophotonic Components from Hexagonal Boron Nitride

Integrated quantum photonics (IQP) provides a path to practical, scalable quantum computation, communications and information processing. Realization of an IQP platform requires controlled engineering of many nanophotonic components. However, the range of materials for monolithic platforms is limited by the simultaneous need for high-quality quantum light sources, high optical performance, and availability of scalable nanofabrication techniques. Here, the fabrication of IQP components from the recently emerged material hexagonal boron nitride (hBN), including tapered waveguides, microdisks, and 1D and 2D photonic crystal cavities, is demonstrated. Resonators with quality factors greater than 4000 are achieved, and proof-of-principle complex, free-standing IQP circuitry fabricated from single-crystal hBN is engineered. The results show the potential of hBN for scalable integrated quantum technologies.