Single photon emitters from quantum engineered hexagonal boron nitride

Hexagonal boron nitride (hBN) is an ultra-wide-bandgap (>6 eV) two-dimensional material that hosts room-temperature single-photon emitters and spin defects, promising a platform for quantum photonics and sensing. However, deterministic control over the emission wavelength, spatial position, single-photon purity, and atomic origins of point defects in hBN remains challenging. Here, we review quantum engineering strategies for point defects in hBN, including high-temperature annealing, plasma treatment, strain engineering, and nanoscale irradiation methods. These approaches enable a progressive transition from random activation to site-specific and atomic-origin-controlled quantum emitter creation with tunable spectral properties. In particular, nanoscale strain and irradiation techniques facilitate precise spatial localization and defect-family selectivity, advancing integration with on-chip photonic circuits. These strategies pave the way for scalable on-chip single photon sources and quantum sensor arrays toward practical quantum technologies based on hBN.