Coupling Spin Defects in Hexagonal Boron Nitride to Monolithic Bullseye Cavities

Color centers in hexagonal boron nitride (hBN) are becoming an increasingly important building block for quantum photonic applications. Herein, we demonstrate the efficient coupling of recently discovered spin defects in hBN to purposely designed bullseye cavities. We show that boron vacancy spin defects couple to the monolithic hBN cavity system and exhibit a 6.5-fold enhancement. In addition, by comparative finite-difference time-domain modeling, we shed light on the emission dipole orientation, which has not been experimentally demonstrated at this point. Beyond that, the coupled spin system exhibits an enhanced contrast in optically detected magnetic resonance readout and improved signal-to-noise ratio. Thus, our experimental results, supported by simulations, constitute a first step toward integration of hBN spin defects with photonic resonators for a scalable spin-photon interface.

Automated summary

Color centers in hexagonal boron nitride (hBN) have shown efficient coupling to bullseye cavities, demonstrating a 6.5-fold enhancement in boron vacancy spin defects. Through finite-difference time-domain modeling, emission dipole orientation and enhanced contrast in optically detected magnetic resonance readout have been elucidated. This paves the way for integrating hBN spin defects with photonic resonators for a scalable spin-photon interface.