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arXiv:2511.08797 · Physical Review Applied

Cold-Atom Buoy: A Differential Magnetic Sensing Technique in Cold Quadrupole Traps

Árpád Kurkó, Dávid Nagy, Alexandra Simon, Thomas W. Clark, András Dombi, Dániel Varga, Francis B. Williams, József Fortágh, Peter Domokos, András Vukics

quant-phcond-mat.quant-gasphysics.atom-phSubmitted Nov 11, 2025• Announced Nov 13, 2025• 0 citations• Revised Mar 11, 2026 (v2)
v1 · Nov 11, 2025v2 · Mar 11, 2026
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Abstract

We present a differential technique for vector magnetic sensing based on a cold-atom cloud in a magnetic quadrupole trap. An external homogeneous magnetic field displaces the trap center in a direction and magnitude proportional to the field. By reversing the quadrupole polarity between experimental shots and comparing the resulting cloud positions, we extract a differential displacement signal that is free from common-mode effects such as gravity and weak magnetic-field inhomogeneities. The signal is directionally proportional to the external field and requires only absorption imaging, without spectroscopic interrogation. Assuming micron-scale position resolution, the technique enables field resolution at the milli-Gauss level. It offers a practical tool for field compensation in magnetically sensitive experimental stages, bridging operational regimes from Earth-level fields to atomic magnetometry. A straightforward extension to full three-dimensional sensing is possible with only a minimal addition to standard cold-atom infrastructure.

Journal reference
Phys. Rev. Applied 25 054063 (2026)
DOI
10.1103/wclj-d912
Comments
25 pages, 11 figures

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