We demonstrate a highly sensitive real-time magnetometry method at two measurement points. This magnetometry method is based on the frequency-division multiplexing of continuous-wave optically detected magnetic resonance. We use two ensembles of nitrogen-vacancy (NV) centers separated by 3.6 mm to measure a magnetic field. A different bias field is applied to the two NV ensembles to resolve the resonance peak for each ensemble in the frequency space and enables the multiplexed magnetometry at the two points. The sensitivities achieved at the measurement points are 21pT/Hz and 22pT/Hz. The proposed magnetometry method can be expanded to include more measurement points and shorter spacing. The capability of real-time measurement at numerous points with short spacing and high sensitivity is beneficial for various applications, including biomagnetic sensing, geophysical research, and material science.
@article{arxiv.2509.20055,
title = {Multichannel highly sensitive diamond quantum magnetometer},
author = {Atsumi Yoshimura and Ayumi Kanamoto and Naota Sekiguchi and Chikara Shinei and Masashi Miyakawa and Takashi Taniguchi and Tokuyuki Teraji and Hiroshi Abe and Shinobu Onoda and Takeshi Ohshima and Takayuki Iwasaki and Mutsuko Hatano},
journal= {arXiv preprint arXiv:2509.20055},
year = {2025}
}