Deterministic integration of quantum emitters and optical cavities in a van der Waals crystal

TL;DR

This paper presents a precise fabrication method for integrating quantum emitters in hexagonal boron nitride with optical cavities, enabling scalable on-chip quantum photonic devices.

Contribution

It introduces a deterministic integration protocol for coupling pre-selected emitters in hBN with optical cavities, overcoming stochastic placement issues.

Findings

Enhanced emission from coupled cavity-emitter systems

Reliable spectral alignment achieved

Scalable fabrication process demonstrated

Abstract

Single-photon emitters in hexagonal boron nitride (hBN) combine bright optical emission with optically addressable spin states, offering a promising platform for integrated quantum photonics. However, their stochastic creation and spectral variability have prevented deterministic integration with photonic cavities. Here we demonstrate a fabrication protocol that enables precise, deterministic coupling of pre-selected visible emitters to circular Bragg grating (CBG) cavities in hBN. By patterning etched alignment markers and performing prefabrication confocal mapping, we locate emitters with sub-micron accuracy and design cavity geometries matched to their zero-phonon line wavelengths. The resulting devices show enhanced emission and reliable spectral alignment between emitter and cavity mode. This work establishes a deterministic cavity-emitter integration scheme in a van der Waals material and provides a scalable route towards on-chip quantum photonic and spin-based platforms using hBN.