Tailoring Single Photon Sources in Hexagonal Boron Nitride via Chemical Vapor Deposition and Nanoscale Focused Ion Beam Milling

Emerging quantum information technologies demand robust, tunable, single photon sources. Solid-state single photon emitters (SPEs) in the two-dimensional material hexagonal boron nitride (hBN) offer unique advantages, including stability and integration potential, yet current fabrication methods lack precise control over the emitter placement and properties. In this work, we demonstrate a high-yield approach to patterning SPE arrays in hBN by combining focused ion beam (FIB) milling with chemical vapor deposition (CVD) of nanocrystalline graphitic carbon. Using statistical design and analysis of experiments, we systematically map a high-dimensional parameter space─spanning FIB exposure and CVD conditions─to identify the optimal regimes for SPE formation and tunability. Our method leverages widely available fabrication tools and provides critical insights into defect activation mechanisms, offering a scalable, reproducible path toward controllable quantum emitter synthesis. Beyond hBN, this approach opens the door to generating defect-based SPEs in other low-defect solid-state materials. The result is a practical and versatile platform for creating quantum light sources tailored for applications in communication, sensing, and computation.