Hexagonal boron nitride (hBN) is gaining considerable attention as a solid-state host of quantum emitters from the ultraviolet to the near-infrared spectral ranges. However, the atomic structures of most of the emitters are speculative or unknown, and emitter fabrication methods typically suffer from poor reproducibility, spatial accuracy, or spectral specificity. Here, we present a robust, electron beam technique for site-specific fabrication of blue quantum emitters with a zero-phonon line at 436 nm (2.8 eV). We show that the emission intensity is proportional to electron dose and that the efficacy of the fabrication method correlates with a defect emission at 305 nm (4.1 eV). We attribute blue emitter generation to the fragmentation of carbon clusters by electron impact and show that the robustness and universality of the emitter fabrication technique are enhanced by a pre-irradiation annealing treatment. Our results provide important insights into photophysical properties and structure of defects in hBN and a framework for site-specific fabrication of quantum emitters in hBN.

Hexagonal boron nitride (hBN) is gaining interest for potential applications in integrated quantum nanophotonics. Yet, to establish hBN as an integrated photonic platform several cornerstones must be established, including the integration and coupling of quantum emitters to photonic waveguides. Supported by simulations, we study the approach of monolithic integration, which is expected to have coupling efficiencies that are ~ 4 times higher than those of a conventional hybrid stacking strategy. We then demonstrate the fabrication of such devices from hBN and showcase the successful integration of hBN single photon emitters with a monolithic waveguide. We demonstrate coupling of single photons from the quantum emitters to the waveguide modes and on-chip detection. Our results build a general framework for monolithically integrated hBN single photon emitter and will facilitate future works towards on-chip integrated quantum photonics with hBN.

Two-dimensional hexagonal boron nitride (hBN) has attracted much attention as a platform for studies of light-matter interactions at the nanoscale, especially in quantum nanophotonics. Recent efforts have focused on spin...

Van der Waals heterostructures offer a unique platform to investigate light matter interaction at the nanoscale. In this work, we explore resonant energy transfer processes between van der Waals materials from two fundamentally different systems: single-photon emitters in two-dimensional hexagonal boron nitride and excitons in transition metal dichalcogenide monolayers. We study the photodynamics between these two systems by performing time-resolved fluorescence spectroscopy. Our results show that colour centres in hexagonal boron nitride do interact with transition metal dichalcogenide excitons and provide important insights into harnessing these interactions in van der Waals heterostructures for advanced nanophotonic devices.

Spin-dependent optical transitions are attractive for a plethora of applications in quantum technologies. Here we report on utilization of high quality ring resonators fabricated from TiO2 to enhance the emission...