Laser activation of single group-IV colour centres in diamond

Xingrui Cheng; Andreas Thurn; Guangzhao Chen; Gareth S Jones; James E Bennett; Maddison Coke; Mason Adshead; Cathryn P Michaels; Osman Balci; Andrea C Ferrari; Mete Atatüre; Richard J Curry; Jason M Smith; Patrick S Salter; Dorian A Gangloff

doi:10.1038/s41467-025-60373-5

Laser activation of single group-IV colour centres in diamond

Nat Commun. 2025 Jun 2;16(1):5124. doi: 10.1038/s41467-025-60373-5.

Authors

Xingrui Cheng^{1

2}, Andreas Thurn^{2

3}, Guangzhao Chen^{1

4}, Gareth S Jones¹, James E Bennett¹, Maddison Coke⁵, Mason Adshead^{5

6}, Cathryn P Michaels³, Osman Balci⁷, Andrea C Ferrari⁷, Mete Atatüre³, Richard J Curry^{5

6}, Jason M Smith⁸, Patrick S Salter⁹, Dorian A Gangloff^{10

11}

Affiliations

¹ Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK.
² Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
³ Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK.
⁴ Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA.
⁵ Photon Science Institute, Faculty of Science and Engineering, University of Manchester, Manchester, M13 9PL, UK.
⁶ Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, University of Manchester, Manchester, M13 9PL, UK.
⁷ Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ, UK.
⁸ Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK. jason.smith@materials.ox.ac.uk.
⁹ Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK. patrick.salter@eng.ox.ac.uk.
¹⁰ Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK. dag50@cam.ac.uk.
¹¹ Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE, UK. dag50@cam.ac.uk.

Abstract

Spin-photon interfaces based on group-IV colour centres in diamond offer a promising platform for quantum networks. A key challenge in the field is realising precise single-defect positioning and activation, which is crucial for scalable device fabrication. Here we address this problem by demonstrating a two-step fabrication method for tin vacancy (SnV^-) centres that uses site-controlled ion implantation followed by local femtosecond laser annealing with in-situ spectral monitoring. The ion implantation is performed with sub-50 nm resolution and a dosage that is controlled from hundreds of ions down to single ions per site, limited by Poissonian statistics. Using this approach, we successfully demonstrate site-selective creation and modification of single SnV^- centres. Our in-situ spectral monitoring opens a window onto materials tuning at the single defect level, and provides new insight into defect structures and dynamics during the annealing process. While demonstrated for SnV^- centres, this versatile approach can be readily generalised to other implanted colour centres in diamond and wide-bandgap materials.