Ultralow-field nuclear magnetic resonance (NMR) provides a new regime for many applications ranging from materials science to fundamental physics. However, the experimentally observed spectra show asymmetric amplitudes, differing greatly from those predicted by the standard theory. Its physical origin remains unclear, as well as how to suppress it. Here we provide a comprehensive model to explain the asymmetric spectral amplitudes, further observe more unprecedented asymmetric spectroscopy and find a way to eliminate it. Moreover, contrary to the traditional idea that asymmetric phenomena were considered as a nuisance, we show that more information can be gained from the asymmetric spectroscopy, e.g., the light shift of atomic vapors and the sign of Landeˊg factor of NMR systems.
@article{arxiv.1902.08073,
title = {Ultralow-field Nuclear Magnetic Resonance Asymmetric Spectroscopy},
author = {Min Jiang and Wenjie Xu and Yunlan Ji and Ji Bian and Shiming Song and Xinhua Peng},
journal= {arXiv preprint arXiv:1902.08073},
year = {2019}
}