Tailoring spin defects in diamond by lattice charging

• Published in: Nature communications 2017-05, Vol.8 (1), p.15409-15409, Article 15409
• Main Authors: Fávaro de Oliveira, Felipe, Antonov, Denis, Wang, Ya, Neumann, Philipp, Momenzadeh, Seyed Ali, Häußermann, Timo, Pasquarelli, Alberto, Denisenko, Andrej, Wrachtrup, Jörg
• Format: Article
• Language: English
• Subjects: 142/126; 639/766/119/1000; 639/766/483/2802; Accuracy; Annealing; Boron; Electrons; Humanities and Social Sciences; multidisciplinary; Nitrogen; Plasma etching; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms15409

Atomic-size spin defects in solids are unique quantum systems. Most applications require nanometre positioning accuracy, which is typically achieved by low-energy ion implantation. A drawback of this technique is the significant residual lattice damage, which degrades the performance of spins in quantum applications. Here we show that the charge state of implantation-induced defects drastically influences the formation of lattice defects during thermal annealing. Charging of vacancies at, for example, nitrogen implantation sites suppresses the formation of vacancy complexes, resulting in tenfold-improved spin coherence times and twofold-improved formation yield of nitrogen-vacancy centres in diamond. This is achieved by confining implantation defects into the space-charge layer of free carriers generated by a boron-doped diamond structure. By combining these results with numerical calculations, we arrive at a quantitative understanding of the formation and dynamics of the implanted spin defects. These results could improve engineering of quantum devices using solid-state systems. Ion implantation is used to introduce spin defects in solids, but it inflicts residual lattice damage, degrading performances. Here the authors demonstrate that the charge state of induced defects influences such damage, and that charging vacancies leads to improved coherence times and yield of centres.