Nitrogen-vacancy quantum defects in diamond offer a promising platform for magnetometry because of their remarkable optical and spin properties. In this Letter, we present a high-sensitivity and wide-bandwidth fiber-based quantum magnetometer for practical applications. By coating the diamond surface with silver reflective film, both the fluorescence collection and excitation efficiency are enhanced. Additionally, tracking pulsed optically detected magnetic resonance spectrum allowed a magnetic field sensitivity of 35 pT/Hz and a bandwidth of 4.1 KHz. Finally, this magnetometer was successfully applied to map the magnetic field induced by the current-carrying copper-wire mesh. Such a stable and compact magnetometry can provide a powerful tool in many areas of physical, chemical, and biological researches.
@article{arxiv.2102.12233,
title = {A high-sensitivity fiber-coupled diamond magnetometer with surface coating},
author = {Shao-Chun Zhang and Hao-Bin Lin and Yang Dong and Bo Du and Xue-Dong Gao and Cui Yu and Zhi-Hong Feng and Xiang-Dong Chen and Guang-Can Guo and Fang-Wen Sun},
journal= {arXiv preprint arXiv:2102.12233},
year = {2021}
}