Plasmon Enhanced Quantum Properties of Single Photon Emitters in Hexagonal Boron Nitride Flakes

Two dimensional (2D) materials such as hexagonal born nitride (hBN) have emerged as promising hosts of single photon sources (SPEs) which exhibits promising optical properties (high brightness, optically accessible spin states, high quantum efficiency, <i>etc</i>.), making them highly desirable elements for integrated quantum photonics [1]. In this study, we create SPEs in thin (thickness ≤ 10 nm) hBN flakes deposited on a Si/SiO2 substrate by using a high-temperature (1100 °C) annealing method under O₂flow and characterize their quantum properties using a home-built confocal fluorescence microscope. We demonstrate plasmonic enhancement of SPE properties by spin-coating of 100 nm Ag nanotubes on top of the hBN flake: a decrease of emission linewidth by 30% and quantum emitter lifetime decrease by 60% [2]. We expect &gt; 2 order of magnitude enhancement of SPE fluorescence when integrating them to optical nanocavities. Such enhancement is supported using COMSOL numerical simulations where hBN flakes are integrated into a composite nanophotonic structure entailing plasmonic effects from silver nanocubes and the optical frequency resonance from the fabricated metallic nanocavity. J. D. Caldwell, et <i>al.</i>, Nat. Rev. Mat. 4, 552-567 (2019). M. Dowran, et <i>al.</i>, under preparation.<br/><br/><b>Acknowledgment:</b> This material is based upon work supported by the National Science Foundation/EPSCoR RII Track-1: Emergent Quantum Materials and Technologies (EQUATE), Award OIA-2044049. The research was partly performed in the Nebraska Nanoscale Facility: National Nanotechnology Coordinated Infrastructure and the Nebraska Center for Materials and Nanoscience (and/or NERCF), which are supported by the National Science Foundation under Award ECCS: 2025298, and the Nebraska Research Initiative.