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

TL;DR

This study uses density functional theory to analyze the stability and electronic properties of NV centers near dislocation cores in diamond, revealing potential for self-assembled linear NV arrays with stable triplet states.

Contribution

It provides the first detailed analysis of NV centers at dislocation cores in diamond, highlighting their lower formation energies and stable configurations suitable for quantum applications.

Findings

NV centers at dislocation cores have formation energies up to 3 eV lower than in bulk diamond.

The lowest energy NV configuration at 30° dislocation cores aligns with the dislocation line.

Hyperfine and zero-field splitting parameters are within 3% of bulk NV centers.

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.