First-principles study of negatively charged nitrogen vacancy and silicon vacancy in diamond in strained environments*

In the last decade, the negatively charged nitrogen vacancy (NV^-) and silicon vacancy (SiV^-) in diamond have been recognized as promising point defects candidates for quantum information technologies. For example, the NV^- center has been recently shown to be an efficient high-pressure quantum sensor [1]. We carried out first-principles calculations based on density functional theory to compute the properties of the NV^- and SiV^- centers in strained environments, including zero-phonon lines (ZPL) and photoluminescence spectra. We also performed photoluminescence measurements, finding good agreement with theoretical predictions. Our results allowed us to solve previous controversies present in the literature [2,3]. Importantly, our findings point at possible ways to improve the performance of the NV^- and SiV^- centers in diamond as quantum sensors.
[1] Hsieh, S., et al. Science 366.6471 (2019): 1349-1354.
[2] Doherty et. al., Phys. Rev. Lett. 112, 047601 (2014).
[3] Lyapin, S. G., et al. Nanosystems: Physics, Chemistry, Mathematics.9.1 (2018).