Alignment of the Diamond Nitrogen Vacancy Center by Strain Engineering

TL;DR

This paper demonstrates that high-temperature annealing under strain can effectively align nitrogen vacancy centers in diamond along a specific crystallographic direction, enhancing their utility in quantum applications.

Contribution

It introduces a theoretical method to control NV center orientation via strain engineering during annealing, a novel approach for optimizing diamond-based quantum devices.

Findings

89% of NVs align along [111] under 2% compressive strain

Alignment achieved at 970°C annealing temperature

Strain engineering enables controlled NV orientation

Abstract

The nitrogen vacancy (NV) center in diamond is a sensitive probe of magnetic field and a promising qubit candidate for quantum information processing. The performance of many NV-based devices improves by aligning the NV(s) parallel to a single crystallographic direction. Using ab initio theoretical techniques, we show that NV orientation can be controlled by high-temperature annealing in the presence of strain under currently accessible experimental conditions. We find that $(89\pm7)\%$ of NVs align along the [111] crystallographic direction under 2\% compressive biaxial strain (perpendicular to [111]) and an annealing temperature of 970$^\circ$C.