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.
@article{arxiv.1806.09816,
title = {Spin properties of NV centers in high-pressure, high-temperature grown diamond},
author = {O. R. Rubinas and V. V. Vorobyov and V. V. Soshenko and S. V. Bolshedvorskii and V. N. Sorokin and A. N. Smolyaninov and V. G. Vins and A. P. Yelisseyev and A. V. Akimov},
journal= {arXiv preprint arXiv:1806.09816},
year = {2018}
}