Narrowband quantum emitters in hexagonal boron nitride with optically addressable spins

Nature Materials (2026)Cite this article Electron spins coupled with optical transitions in solids stand out as a promising platform for developing spin-based quantum technologies. Recently, hexagonal boron nitride has emerged as a promising host for optically addressable spin systems. However, controlled generation of isolated single-photon emitters with predetermined spin transitions has remained elusive. Here we report on a single-step thermal processing of hexagonal boron nitride flakes that produces high-density, narrowband quantum emitters with optically active spin transitions, with over 25% of the emitters exhibiting a clear signature of an optical spin read-out at room temperature. 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 hexagonal boron nitride and paves the way for single spin–photon interfaces in layered materials with applications in quantum sensing and information processing.This is a preview of subscription content, access via your institution Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription $32.99 / 30 days cancel any timeSubscribe to this journal Receive 12 print issues and online access $259.00 per yearonly $21.58 per issueBuy this articleUSD 39.95Prices may be subject to local taxes which are calculated during checkoutThe main data supporting the findings of this study are available within the article and its Supplementary Information. Source data are provided with this paper.Stas, P.-J. et al. Robust multi-qubit quantum network node with integrated error detection. Science 378, 557–560 (2022).Article CAS PubMed Google Scholar Hermans, S. L. N. et al. Qubit teleportation between non-neighbouring nodes in a quantum network. Nature 605, 663–668 (2022).Article CAS PubMed PubMed Central Google Scholar Degen, C. L., Reinhard, F. & Cappellaro, P. Quantum sensing. Rev. Mod. Phys. 89, 035002 (2017).Article Google Scholar Wang, J.-F. et al. Magnetic detection under high pressures using designed silicon vacancy centres in silicon carbide. Nat. Mater. 22, 489–494 (2023).Article CAS PubMed Google Scholar Siyushev, P. et al. Photoelectrical imaging and coherent spin-state readout of single nitrogen-vacancy centers in diamond. Science 363, 728–731 (2019).Article CAS PubMed Google Scholar Chejanovsky, N. et al. Single-spin resonance in a van der Waals embedded paramagnetic defect. Nat. Mater. 20, 1079–1084 (2021).Article CAS PubMed Google Scholar Luo, J., Geng, Y., Rana, F. & Fuchs, G. D. Room temperature optically detected magnetic resonance of single spins in GaN. Nat. Mater. 23, 512–518 (2024).Article CAS PubMed Google Scholar Singh, P. et al. Violet to near-infrared optical addressing of spin pairs in hexagonal boron nitride. Adv. Mater. 37, 2414846 (2025).Article CAS PubMed PubMed Central Google Scholar Gottscholl, A. et al. Initialization and read-out of intrinsic spin defects in a van der Waals crystal at room temperature. Nat. Mater. 19, 540–545 (2020).Article CAS PubMed Google Scholar Durand, A. et al. Optically active spin defects in few-layer thick hexagonal boron nitride. Phys. Rev. Lett. 131, 116902 (2023).Article CAS PubMed Google Scholar Hennessey, M. et al. Engineering boron vacancy defects in boron nitride nanotubes. ACS Appl. Mater. Interfaces 16, 57552–57557 (2024).Article CAS PubMed Google Scholar Gao, X. et al. Quantum sensing of paramagnetic spins in liquids with spin qubits in hexagonal boron nitride. ACS Photon. 10, 2894–2900 (2023).Article CAS Google Scholar Reimers, J. R. et al. Photoluminescence, photophysics, and photochemistry of the VB− defect in hexagonal boron nitride. Phys. Rev. B 102, 144105 (2020).Article CAS Google Scholar Stern, H. L. et al. Room-temperature optically detected magnetic resonance of single defects in hexagonal boron nitride. Nat. Commun. 13, 618 (2022).Article CAS PubMed PubMed Central Google Scholar Stern, H. L. et al. A quantum coherent spin in hexagonal boron nitride at ambient conditions. Nat. Mater. 23, 1379–1385 (2024).Article CAS PubMed PubMed Central Google Scholar Gao, X. et al. Nanotube spin defects for omnidirectional magnetic field sensing. Nat. Commun. 15, 7697 (2024).Article CAS PubMed PubMed Central Google Scholar Scholten, S. C. et al. Multi-species optically addressable spin defects in a van der Waals material. Nat. Commun. 15, 6727 (2024).Article CAS PubMed PubMed Central Google Scholar Guo, N.-J. et al. Coherent control of an ultrabright single spin in hexagonal boron nitride at room temperature. Nat. Commun. 14, 2893 (2023).Article CAS PubMed PubMed Central Google Scholar Patel, R. N. et al. Room temperature dynamics of an optically addressable single spin in hexagonal boron nitride. Nano Lett. 24, 7623–7628 (2024).Article CAS PubMed Google Scholar Robertson, I. O. et al. A charge transfer mechanism for optically addressable solid-state spin pairs. Nat. Phys. 21, 1981–1987 (2025).Article CAS Google Scholar Onodera, M. et al. Carbon annealed HPHT-hexagonal boron nitride: exploring defect levels using 2D materials combined through van der Waals interface. Carbon 167, 785–791 (2020).Article CAS Google Scholar Liu, W. et al. Spin-active defects in hexagonal boron nitride. Mater. Quantum Technol. 2, 032002 (2022).Maciaszek, M., Razinkovas, L. & Alkauskas, A. Thermodynamics of carbon point defects in hexagonal boron nitride. Phys. Rev. Mater. 6, 014005 (2022).Article CAS Google Scholar Liu, H. et al. Rational control on quantum emitter formation in carbon doped monolayer hexagonal boron nitride. ACS Appl. Mater. Interfaces 14, 3189–3198 (2022).Article CAS PubMed Google Scholar Xu, X. et al. Creating quantum emitters in hexagonal boron nitride deterministically on chip-compatible substrates. Nano Lett. 21, 8182–8189 (2021).Article CAS PubMed Google Scholar Mendelson, N. et al. Identifying carbon as the source of visible single-photon emission from hexagonal boron nitride. Nat. Mater. 20, 321–328 (2021).Article CAS PubMed Google Scholar Whitefield, B., Toth, M., Aharonovich, I., Tetienne, J.-P. & Kianinia, M. Magnetic field sensitivity optimization of negatively charged boron vacancy defects in hBN. Adv. Quantum Technol. 8, 2300118 (2025).Tetienne, J. P. et al. Magnetic-field-dependent photodynamics of single NV defects in diamond: an application to qualitative all-optical magnetic imaging. New J. Phys. 14, 103033 (2012).Article Google Scholar Clua-Provost, T. et al. Spin-dependent photodynamics of boron-vacancy centers in hexagonal boron nitride. Phys. Rev. B 110, 014104 (2024).Article CAS Google Scholar Evans, E. W. et al. Magnetic field effects in flavoproteins and related systems. Interface Focus 3, 20130037 (2013).Article PubMed PubMed Central Google Scholar Steiner, U. E. & Ulrich, T. Magnetic field effects in chemical kinetics and related phenomena. Chem. Rev. 89, 51–147 (1989).Article CAS Google Scholar Mohajerani, S. S. et al. Narrowband quantum light emission from oxygen-related color centers in hexagonal boron nitride. ACS Photon. 11, 2359–2367 (2024).Article CAS Google Scholar Dowran, M. et al. Plasmonic nanocavity to boost single photon emission from defects in thin hexagonal boron nitride. Laser Photon. Rev. 19, 2400705 (2024).Chen, Y. et al. Generation of high-density quantum emitters in high-quality, exfoliated hexagonal boron nitride. ACS Appl. Mater. Interfaces 13, 47283–47292 (2021).Article CAS PubMed Google Scholar Comtet, J. et al. Wide-field spectral super-resolution mapping of optically active defects in hexagonal boron nitride. Nano Lett. 19, 2516–2523 (2019).Article CAS PubMed Google Scholar Vogl, T., Lu, Y. & Koy Lam, P. Room temperature single photon source using fiber-integrated hexagonal boron nitride. J. Phys. D Appl. Phys. 50, 295101 (2017).Article Google Scholar Xu, Z. Q. et al. Single photon emission from plasma treated 2D hexagonal boron nitride. Nanoscale 10, 7957–7965 (2017).Article Google Scholar Zhong, D. et al. Carbon-related quantum emitter in hexagonal boron nitride with homogeneous energy and 3-fold polarization. Nano Lett. 24, 1106–1113 (2024).Article CAS PubMed PubMed Central Google Scholar Jara, C. et al. First-principles identification of single photon emitters based on carbon clusters in hexagonal boron nitride. J. Phys. Chem. A 125, 1325–1335 (2021).Article CAS PubMed Google Scholar Li, K., Smart, T. J. & Ping, Y. Carbon trimer as a 2 eV single-photon emitter candidate in hexagonal boron nitride: a first-principles study. Phys. Rev. Mater. 6, L042201 (2022).Article CAS Google Scholar Golami, O. et al. Ab initio and group theoretical study of properties of a carbon trimer defect in hexagonal boron nitride. Phys. Rev. B 105, 184101 (2022).Article CAS Google Scholar Gao, X. et al. Single nuclear spin detection and control in a van der Waals material. Nature 643, 943–949 (2025).Article PubMed PubMed Central Google Scholar Download referencesWe acknowledge financial support from the Australian Research Council (CE200100010, FT220100053, DP240103127, FT200100073 and DP250100973), the Air Force Office of Scientific Research (FA2386-25-1-4044) and the UTS node of the Australian National Nano Fabrication facility (ANFF) for access to facilities. I.O.R. is supported by an Australian Government Research Training Program Scholarship. K.W. and T.T. acknowledge support from the Japan Society for Promotion of Science (JSPS) KAKENHI (grant nos. 21H05233 and 23H02052), the Core Research for Evolutional Science and Technology (CREST, JPMJCR24A5), Japan Science and Technology Agency (JST) and the World Premier International (WPI) Research Center Initiative, Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. This work was also supported by the National Research, Development and Innovation Office of Hungary (NKFIH) within the project FK 145395. The theoretical project was also funded by the European Commission within Horizon Europe projects (grant nos. 101156088 and 101129663). The computations were enabled by resources provided by the National Academic Infrastructure for Supercomputing in Sweden (NAISS) and the Swedish National Infrastructure for Computing (SNIC) at NSC, partially funded by the Swedish Research Council through grant agreement nos. 2022-06725 and 2018-05973. The authors also acknowledge KIFÜ for awarding us computational resources at the Komondor supercomputer in Hungary.These authors contributed equally: Benjamin Whitefield, Helen Zhi Jie Zeng.School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, New South Wales, AustraliaBenjamin Whitefield, Helen Zhi Jie Zeng, James Liddle-Wesolowski, Milos Toth, Igor Aharonovich & Mehran KianiniaARC Centre of Excellence for Transformative Meta-Optical Systems, University of Technology Sydney, Ultimo, New South Wales, AustraliaBenjamin Whitefield, James Liddle-Wesolowski, Milos Toth, Igor Aharonovich & Mehran KianiniaSchool of Science, RMIT University, Melbourne, Victoria, AustraliaIslay O. Robertson & Jean-Philippe TetienneDepartment of Physics of Complex Systems, Eötvös Loránd University, Budapest, HungaryÁdám Ganyecz & Viktor IvádyMTA–ELTE Lendület ‘Momentum’ NewQubit Research Group, Budapest, HungaryÁdám Ganyecz & Viktor IvádyResearch Center for Electronic and Optical Materials, National Institute for Materials Science, Tsukuba, JapanKenji WatanabeResearch Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, JapanTakashi TaniguchiSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarSearch author on:PubMed Google ScholarM.K. and I.A. designed the experiments. B.W., H.Z.J.Z. and M.K. wrote the paper with contributions from all authors. H.Z.J.Z., B.W. and J.L.-W. performed the experimental measurements and data analysis. I.O.R., J.-P.T., A.G. and V.I. performed the computational calculations. T.T. and K.W. grew the hBN and c-hBN. B.W. and M.K. performed the ODMR experiments. M.T., I.A. and M.K. supervised the project. The co-first-authorship order was determined via a single coin toss. All authors discussed the results and contributed to the paper.Correspondence to Igor Aharonovich or Mehran Kianinia.The authors declare no competing interests.Nature Materials thanks the anonymous reviewers for their contribution to the peer review of this work.Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.Supplementary Sections 1 –3, Figures 1 –20 and Tables 1 –7.Source data for Fig. 1 plots.Source data for Fig. 2 plots.Source data for Fig. 3 plots.Source data for Fig. 4 plots.Source data for Fig. 5 plots.Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.Reprints and permissionsWhitefield, B., Zeng, H.Z.J., Liddle-Wesolowski, J. et al. Narrowband quantum emitters in hexagonal boron nitride with optically addressable spins. Nat. Mater. (2026). https://doi.org/10.1038/s41563-025-02458-6Download citationReceived: 23 January 2025Accepted: 26 November 2025Published: 27 January 2026Version of record: 27 January 2026DOI: https://doi.org/10.1038/s41563-025-02458-6Anyone you share the following link with will be able to read this content:Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative