Quantum diamond magnetometers using lock-in detection have successfully detected weak bio-magnetic fields from neurons, a live mammalian muscle, and a live mouse heart. This opens up the possibility of quantum diamond magnetometers visualizing microscopic distributions of the bio-magnetic fields. Here, we demonstrate a lock-in-based wide-field quantum diamond microscopy, achieving a mean volume-normalized per pixel sensitivity of 43.9 nTμm1.5/Hz0.5. We optimize the sensitivity by implementing a double resonance with hyperfine driving and magnetic field alignment along the <001> orientation of the diamond. Additionally, we show that sub-ms temporal resolution (∼ 0.4 ms) can be achieved while keeping the per-pixel sensitivity at a few tens of nanotesla per second using quantum diamond microscopy. This lock-in-based diamond quantum microscopy could be a step forward in mapping functional activity in neuronal networks in micrometer spatial resolution.
@article{arxiv.2301.05853,
title = {Quantum diamond microscopy with optimized magnetic field sensitivity and sub-ms temporal resolution},
author = {Sangwon Oh and Seong-Joo Lee and Jeong Hyun Shim and Nam Woong Song and Truong Thi Hien},
journal= {arXiv preprint arXiv:2301.05853},
year = {2023}
}