Generation of Spin Defects in Hexagonal Boron Nitride
Two-dimensional hexagonal boron nitride offers intriguing opportunities for advanced studies of light–matter interaction at the nanoscale, specifically for realizations in quantum nanophotonics. Here, we demonstrate the generation of optically addressable spin defects based on the negatively charged boron vacancy (VB–) center. We show that these centers can be created in exfoliated hexagonal boron nitride using a variety of focused ion beams (nitrogen, xenon, and argon). Using a combination of laser and resonant microwave excitation, we carry out optically detected magnetic resonance spectroscopy measurements, which reveal a zero-field ground state splitting for the defect of ∼3.46 GHz. We also perform photoluminescence excitation spectroscopy and temperature-dependent photoluminescence measurements to elucidate the photophysical properties of the VB– centers. Our results are important for advanced quantum and nanophotonics realizations involving manipulation and readout of spin defects in hexagonal boron nitride.