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arXiv · 2209.13086

Magnetic-field-independent spin-exchange relaxation-free magnetometer

Mark Dikopoltsev·Uriel Levy·Or Katz
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Abstract

SERF magnetometers based on dense ensembles of alkali-metal spins are precision quantum sensors that hold the record of measured and projected sensitivity to magnetic fields, in the $\mu\textrm{G}-\textrm{mG}$ range. At geomagnetic fields however, these sensors quickly lose their magnetic sensitivity due to spin decoherence by random spin-exchange collisions. Here we discover that atoms with nuclear spin $I=1/2$ can operate in the Spin-Exchange Relaxation Free (SERF) regime even at high magnetic field. We counter-intuitively show that frequent collisions between a dense and optically-inaccessible $(I=1/2)$ gas with another optically-accessible spin gas ($I>1/2$) improve the fundamental magnetic sensitivity of the latter. We analyze the performance of a dual-specie potassium and atomic hydrogen magnetometer, and project a fundamental sensitivity of about $10\,\mathrm{aT}\sqrt{\mathrm{cm}^3/\mathrm{Hz}}$ at geomagnetic fields for feasible experimental conditions.

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Mark Dikopoltsev, Uriel Levy, Or Katz. 2022-09-27. Magnetic-field-independent spin-exchange relaxation-free magnetometer. https://doi.org/10.1103/physreva.111.032602

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