Stability and electronic structure of NV centers at dislocation cores in diamond

Abstract: We present a density functional theory analysis of the negatively charged nitrogen-vacancy (NV) defect complex located at or close to the core of 30$^\circ$ and 90$^\circ$ partial glide dislocations in diamond. Formation energies, electronic densities of states, structural deformations, hyperfine structure and zero-field splitting parameters of NV centers in such structurally distorted environments are analyzed. The formation energies of the NV centers are up to 3 eV lower at the dislocation cores compared to the bulk values of crystalline diamond. We found that the lowest energy configuration of the NV center at the core of a 30$^\circ$ partial glide dislocation is realized when the axis of the NV center is oriented parallel to the dislocation line. This special configuration has a stable triplet ground state. Its hyperfine constants and zero field splitting parameters deviate by only 3% from values of the bulk NV center. Hence, this is an interesting candidate for a self-assembly of a linear array of NV centers along the dislocation line.