First-Principles Study of NV Centers Near Extended Defects

We present a density functional theory analysis of the negatively charged nitrogen-vacancy (NV \(^-\) ) defect complex located at or in the vicinity of (001) and (111) surfaces as well as 30 \(^{\circ }\) and 90 \(^{\circ }\) partial glide dislocations in diamond. Formation energies, electronic density of states, geometrical deformations, hyperfine structure and zero-field splitting parameters of NV \(^-\) centers in such distorted environments are analyzed. The formation energies of the NV \(^-\) centers at the dislocation cores are up to 3 eV reduced compared to the bulk of diamond whereas near the surfaces the change of the formation energy is not significant ( \(\sim \) 0.1 eV). For the 30 \(^{\circ }\) partial glide dislocation the lowest energy configuration, where the NV \(^-\) axis is oriented parallel to the dislocation line, exhibits a stable triplet ground state. This lowest energy configuration of NV \(^-\) center at the core of 30 \(^{\circ }\) partial glide dislocation has hyperfine constants and ZFS values which deviate by \(3\%\) from the NV \(^-\) bulk values and is thus an interesting candidate for self-assembled NV \(^-\) arrays. These crucial theoretical results required time consuming electronic structure calculations, for which we used the HoreKa computing cluster.