Fig. 1: Activation of localized ensembles of SPEs on a hBN flake.

a SEM image of a high-purity hBN flake of about 15 × 20 μm and 60 nm thickness. b Confocal map of the irradiated zone (blue rectangle in a) with eight irradiation spots (orange dashed lines). (c) and (d) Low-temperature spectra of the eight spots with two different spectral resolutions, showing a reproducible ZPL within 0.7 nm.