Quantum sensing based on nitrogen-vacancy (NV) centers in diamond has been developed as a powerful tool for microscopic magnetic resonance. However, the reported sensor-to-sample distance is limited within tens of nanometers because the signal of spin fluctuation decreases cubically with the increasing distance. Here we extend the sensing distance to tens of micrometers by detecting spin polarization rather than spin fluctuation. We detected the mesoscopic magnetic resonance spectra of polarized electrons of a pentacene-doped crystal, measured its two typical decay times and observed the optically enhanced spin polarization. This work paves the way for the NV-based mesoscopic magnetic resonance spectroscopy and imaging at ambient conditions.
@article{arxiv.1706.03939,
title = {Mesoscopic magnetic resonance spectroscopy with a remote spin sensor},
author = {Tianyu Xie and Fazhan Shi and Sanyou Chen and Maosen Guo and Yisheng Chen and Yixing Zhang and Yu Yang and Xingyu Gao and Xi Kong and Pengfei Wang and Kenichiro Tateishi and Tomohiro Uesaka and Ya Wang and Bo Zhang and Jiangfeng Du},
journal= {arXiv preprint arXiv:1706.03939},
year = {2018}
}