Hexagonal boron nitride (h-BN) 2D nanoscale devices for classical and quantum signal transduction

Hexagonal boron nitride (h-BN) crystals possess ultrawide electronic bandgap of 5.9 eV and excellent chemical and thermal stability. Nanometer-scale thin films and atomic layers derived from the layered bulk of h-BN crystals have been widely adopted for enabling new two-dimensional (2D) devices and systems, thanks to its excellent dielectric, optical, mechanical, and thermal properties. Lately, h-BN thin layers have also emerged as an attractive material and device platform for nanoscale optics, photonics, and quantum engineering. In this proceedings paper, we report on some of our studies and initial results toward developing integrated photonic circuitry based on this van der Waals (vdW) layered crystal. The first part summarizes our effort on the creation and optical characterization of defect-related quantum emission in exfoliated and dry-transferred h-BN flakes. Based on the statistics from our measurements and state-of-the-art knowledge in the field, we have identified a group of emitters with emission wavelength around 710 nm exhibiting large Debye-Waller (DW) factor. We then describe optical waveguide and cavity designs at the wavelength range of interest, with the aim of achieving high optical cooperativity. Combined with our studies in ultrathin h-BN crystalline nanomechanical resonators and phononic waveguides, these new explorations in quantum emitters will help pave the way to facilitating h-BN photonic devices and integrated systems for both classical and quantum applications.