Electron spins coupled with optical transitions in solids stand out as a promising platform for developing spin-based quantum technologies. Recently, hexagonal boron nitride (hBN) - a layered Van der Waals (vdW) crystal, has emerged as a promising host for optically addressable spin systems. However, to date, on-demand generation of isolated single photon emitters with pre-determined spin transitions has remained elusive. Here, we report on a single step, thermal processing of hBN flakes that produces high density, narrowband, quantum emitters with optically active spin transitions. Remarkably, over 25% of the emitters exhibit a clear signature of an optical spin readout at room temperature, surpassing all previously reported results by an order of magnitude. The generated spin defect complexes exhibit both S = 1 and S = 1/2 transitions, which are explained by charge transfer from strongly to weakly coupled spin pairs. Our work advances the understanding of spin complexes in hBN and paves the way for single spin - photon interfaces in layered vdW materials with applications in quantum sensing and information processing.
@article{arxiv.2501.15341,
title = {Generation of narrowband quantum emitters in hBN with optically addressable spins},
author = {Benjamin Whitefield and Helen Zhi Jie Zeng and James Liddle-Wesolowski and Islay O. Robertson and Viktor Ivády and Kenji Watanabe and Takashi Taniguchi and Milos Toth and Jean-Philippe Tetienne and Igor Aharonovich and Mehran Kianinia},
journal= {arXiv preprint arXiv:2501.15341},
year = {2025}
}