Ab initio supercell calculations on nitrogen-vacancy center in diamond: its electronic structure and hyperfine tensors

TL;DR

This study uses ab initio supercell calculations to analyze the electronic structure and hyperfine tensors of the nitrogen-vacancy center in diamond, providing detailed insights into its properties relevant for quantum information applications.

Contribution

It offers the first detailed ab initio analysis of the nitrogen-vacancy center's electronic structure and hyperfine interactions, including excited state estimates and spatial hyperfine distribution.

Findings

Hyperfine constants are spread along a plane around the defect.

Measurable hyperfine interactions occur within 7 Å of the vacancy.

Results impact understanding of electron spin decoherence in diamond.

Abstract

The nitrogen-vacancy center in diamond is a promising candidate for realizing the spin qubits concept in quantum information. Even though this defect is known for a long time, its electronic structure and other properties have not yet been explored in detail. We study the properties of the nitrogen-vacancy center in diamond through density functional theory within the local spin density approximation, using supercell calculations. While this theory is strictly applicable for ground state properties, we are able to give an estimate for the energy sequence of the excited states of this defect. We also calculate the hyperfine tensors in the ground state. The results clearly show that: (i) the spin density and the appropriate hyperfine constants are spread along a plane and unevenly distributed around the core of the defect; (ii) the measurable hyperfine constants can be found within about 7 A from the vacancy site. These results have important implications on the decoherence of the electron spin which is crucial in realizing the spin qubits in diamond.