Coupling spin defects in hexagonal boron nitride to monolithic bullseye cavities

TL;DR

This paper demonstrates the efficient coupling of spin defects in hexagonal boron nitride to monolithic bullseye cavities, significantly enhancing emission and readout contrast, advancing scalable quantum photonic integration.

Contribution

It introduces a monolithic hBN cavity system that enhances emission and readout of spin defects, supported by experimental results and simulations, for quantum photonic applications.

Findings

Order of magnitude emission enhancement

Improved optically detected magnetic resonance contrast

Supported by finite difference time domain modelling

Abstract

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 the all monolithic hBN cavity system exhibits an order of magnitude enhancement in the emission of the coupled boron vacancy spin defects. In addition, by comparative finite difference time domain modelling, 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 towards integration of hBN spin defects with photonic resonators for a scalable spin photon interface.