Electrometry of extremely-low frequencies from kHz to sub-Hz with a Rydberg-atom sensor

Abstract:Rydberg-atom electric field sensing has shown great potential from near-DC to THz with state-of-the-art measurement metrics realized in sensitivity, phase extraction, multi-band receptivity, etc. While Rydberg-atom sensors have shown exceptional performance in the GHz regime, low-frequency operation has remained challenging because of electric-field-screening in conventional vapor cells, which suppresses externally applied fields. We overcome this limitation by combining auxiliary modulation and lock-in detection with a paraffin-coated vapor cell, and demonstrate an electrode-free, wideband method for sensing frequencies, ranging from 0.5 Hz to 10 kHz. Our work extends Rydberg-atom sensor range to VLF, ULF, SLF, ELF and sub-ELF frequency bands. In our method, high state-of-the-art sensitivities have been achieved - 819 $\mu$V/cm/$\sqrt{\text{Hz}}$ for 1 Hz, 33 $\mu$V/cm/$\sqrt{\text{Hz}}$ for 10 Hz, 10 $\mu$V/cm/$\sqrt{\text{Hz}}$ for 100 Hz and 2 $\mu$V/cm/$\sqrt{\text{Hz}}$ for 1 kHz.

Quantum Physics (quant-ph); Applied Physics (physics.app-ph); Atomic Physics (physics.atom-ph)

arXiv:2603.13827 [quant-ph]

(or arXiv:2603.13827v2 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2603.13827 Focus to learn more arXiv-issued DOI via DataCite

EPJ Quantum Technol. 13, 87 (2026)

https://doi.org/10.1140/epjqt/s40507-026-00550-7 Focus to learn more DOI(s) linking to related resources

arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.

Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.

Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.