Abstract
Single-photon emitters serve as building blocks for many emerging concepts in quantum photonics. The recent identification of bright, tunable and stable emitters in hexagonal boron nitride (hBN) has opened the door to quantum platforms operating across the infrared to ultraviolet spectrum. Although it is widely acknowledged that defects are responsible for single-photon emitters in hBN, crucial details regarding their origin, electronic levels and orbital involvement remain unknown. Here we employ a combination of resonant inelastic X-ray scattering and photoluminescence spectroscopy in defective hBN, unveiling an elementary excitation at 285 meV that gives rise to a plethora of harmonics correlated with single-photon emitters. We discuss the importance of N π* anti-bonding orbitals in shaping the electronic states of the emitters. The discovery of elementary excitations in hBN provides fundamental insights into quantum emission in low-dimensional materials, paving the way for future investigations in other platforms.
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Data availability
Relevant data are available from the corresponding authors upon reasonable request.
Code availability
The DAP analysis code is available from the corresponding authors upon reasonable request.
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Acknowledgements
We thank A. Gali for fruitful discussions. Work at Brookhaven National Laboratory was supported by the US Department of Energy (DOE) Office of Science under contract no. DE-SC0012704 (J.P., Y.G., J.L., S.F. and V.B.). This work was also supported by the Laboratory Directed Research and Development project of Brookhaven National Laboratory No. 21-037 (J.P. and S.F.) and by the US DOE Office of Science, Early Career Research Program (V.B. and Y.G). This research used Beamline 2-ID of the National Synchrotron Light Source II, a US DOE Office of Science User Facility, operated for the DOE Office of Science by Brookhaven National Laboratory under contract no. DE-SC0012704. Work at CUNY is supported by the National Science Foundation (NSF) (grant no. DMR-2044281) (G.G.), the physics department of the Graduate Center of CUNY and the Advanced Science Research Center (E.M., J.M.W., S.B.C. and G.G.) and the Research Foundation through PSC-CUNY award no. 64510-00 52 (G.G.). K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by MEXT, Japan (grant no. JPMXP0112101001), and JSPS KAKENHI (grant nos. 19H05790, 20H00354 and 21H05233).
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J.P. and G.G. conceived the project. J.P., Y.G., J.L., S.F. and V.B. performed the RIXS experiments. T.T. and K.W. synthesized the high-quality hBN. E.M. and G.G. developed the material process to generate the defective hBN. E.M. prepared the pristine and highly defective hBN samples. E.M. performed the PL experiments with the help of J.M.W., S.B.C. and G.G. E.M., J.M.W. and G.G. developed the fitting methods. J.P. and G.G. wrote the manuscript with input from all authors.
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Pelliciari, J., Mejia, E., Woods, J.M. et al. Elementary excitations of single-photon emitters in hexagonal boron nitride. Nat. Mater. (2024). https://doi.org/10.1038/s41563-024-01866-4
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DOI: https://doi.org/10.1038/s41563-024-01866-4