Spatial control of single-photon emitters in gallium nitride via dose-engineered focused ion beam processing

Single-photon emitters (SPEs) in solid-state materials are key components for emerging quantum technologies, but their random spatial distribution and lack of spatial isolation remain major obstacles to scalable device integration. Here, we demonstrate that dose-engineered Ga+ focused ion beam irradiation enables control over defect-related luminescence and spatial localization of SPEs in gallium nitride (GaN). High-dose irradiation effectively suppresses defect-related emission and deactivates optically active centers in the surrounding regions, while low-dose irradiation followed by thermal annealing promotes the formation of SPEs. By combining low- and high-dose regions within a single patterned structure, emitters are preferentially formed and emerge within predefined low-dose areas, while competing emission is eliminated in the surrounding regions. These results establish a practical and fabrication-compatible strategy for spatial control of quantum emitters in GaN, providing a pathway toward scalable integrated quantum photonic devices.