Spin properties of NV centers in high-pressure, high-temperature grown diamond

TL;DR

This paper demonstrates that high-pressure, high-temperature growth techniques can produce diamond with NV centers exhibiting near-maximal coherence times, enhancing the potential for high-sensitivity diamond-based sensors.

Contribution

It introduces a high-pressure, high-temperature growth method that achieves high NV coherence times, comparable to or better than traditional methods, for improved sensor performance.

Findings

Achieved near-maximal T2* coherence times limited by nuclear spins or electron spins.

Hahn-echo T2 coherence times are reasonably high.

High-pressure, high-temperature technique rivals chemical vapor deposition in sensor development.

Abstract

The sensitivity of magnetic and electric field sensors based on nitrogen-vacancy (NV) center in diamond strongly depends on the available concentration of NV and their coherence properties. Achieving high coherence times simultaneously with high concentration is a challenging experimental task. Here, we demonstrate that by using a high-pressure, high-temperature growing technique, one can achieve nearly maximally possible effective coherence T2* times, limited only by carbon nuclear spins at low nitrogen concentrations or nitrogen electron spin at high nitrogen concentrations. Hahn-echo T2 coherence times were also investigated and found to demonstrate reasonable values. Thus, the high-pressure, high-temperature technique is a strong contender to the popular chemical vapor deposition method in the development of high-sensitivity, diamond-based sensors.