Ab initio study of defect interactions between the negatively charged nitrogen vacancy centre and the carbon self-interstitial in diamond

Fabrication techniques for nitrogen-vacancy centres in diamond require the creation of Frenkel defects (vacancy-interstitial pairs) the components of which can interact with formed NV centres affecting their photophysical properties. Here we use Density Functional Theory simulations of inter-defect electronic and strain interactions to explore how the NV centre and carbon self-interstitial interact in different configurations. We find that hybridization occurs between the NV centre e-orbitals and the carbon self-interstitial when an interstitial is present on the vacancy side of the NV centre. We propose that this phenomenon may explain the fluorescence blinking of NV centres observed during annealing. This article is part of the Theo Murphy meeting issue 'Diamond for quantum applications'.