2023/09/21 by Hamish A. M. Taylor, Christopher C. Bounds, Taylor, Hamish A. M. +5 · 1 citation
Economics, Econometrics and Finance · Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #Complex Systems and Time Series Analysis #FOS: Physical sciences #Quantum Physics (quant-ph)
paper · pdf · doi:10.48550/arxiv.2309.11825
openalex publication_date 2023/09/21 · openalex created_date 2023/09/23 · openalex updated_date 2026/07/28
Cold atom magnetometers exploit a dense ensemble of quanta with long coherence times to realise leading sensitivity on the micrometer scale. Configured as a Ramsey interferometer, a cold atom sensor can approach atom shot-noise limited precision but suffers from fringe ambiguity, producing gross errors when the field falls outside a narrow predefined range. We describe how Hilbert-demodulated optical magnetometry can be realised on cold atom sensors to provide field measurements both precise and unambiguous. Continuous reconstruction of the Larmor phase allows us to determine the dc magnetic field unambiguously in an unshielded environment, as well as measure ac variation of the field, in a single shot. The ac measurement allows us to characterize, and then neutralise, line-synchronous magnetic interference, extending reconstruction times. Using 1.6 × 106 87Rb atoms in a volume of (68 μm)3, we measure a test field to be 86.0121261(4) μT in a single shot, achieving dc sensitivity of 380 fT in a duration of 1000 ms. Our results demonstrate that Hilbert-demodulated optical readout yields metrologically-significant sensitivity without the fringe ambiguity inherent to Ramsey interferometry.