Abstract
High-yield engineering and characterization of cavity–emitter coupling is an outstanding challenge in developing scalable quantum network nodes. Ex situ defect formation systems prevent real-time analysis, and previous in situ methods are limited to bulk substrates or require further processing to improve the emitter properties1,2,3,4,5,6. Here we demonstrate the direct laser writing of cavity-integrated spin defects using a nanosecond pulsed above-bandgap laser. Photonic crystal cavities in 4H-silicon carbide serve as a nanoscope monitoring silicon-monovacancy defect formation within the approximately 200 nm3 cavity-mode volume. We observe spin resonance, cavity-integrated photoluminescence and excited-state lifetimes consistent with conventional defect formation methods, without the need for post-irradiation thermal annealing. We further find an exponential reduction in excited-state lifetime at fluences approaching the cavity amorphization threshold and show the single-shot annealing of intrinsic background defects at silicon-monovacancy formation sites. This real-time in situ method of localized defect formation, paired with cavity-integrated defect spins, is necessary towards engineering cavity–emitter coupling for quantum networking.
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Data availability
The data that support the findings of this work are presented in the Letter and the Supplementary Information. Source data are provided with this paper.
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Acknowledgements
We thank X. Zhang for fabrication support. This work was supported by the Science and Technology Center for Integrated Quantum Materials, NSF grant no. DMR-1231319. Portions of this work were performed at the Harvard University Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under NSF award no. ECCS-2025158. A.M.D. acknowledges funding from the Science and Technology Center for Integrated Quantum Materials, NSF grant no. DMR-1231319. J.R.D. acknowledges funding from NSF RAISE-TAQS Award 1839164. M.S. acknowledges funding from a NASA Space Technology Graduate Research Fellowship. M.Y. acknowledges funding from the Department of Defense (DoD) through the National Defense Science and Engineering Graduate (NDSEG) Fellowship Program.
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A.M.D., J.R.D. and E.L.H. designed the research. A.M.D. and J.R.D. performed all the measurements and data analysis, with assistance from M.S. and M.Y. All the authors contributed to preparing the manuscript.
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Day, A.M., Dietz, J.R., Sutula, M. et al. Laser writing of spin defects in nanophotonic cavities. Nat. Mater. 22, 696–702 (2023). https://doi.org/10.1038/s41563-023-01544-x
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DOI: https://doi.org/10.1038/s41563-023-01544-x
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