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arXiv · 2603.08594

An Accurate Vector Magnetometer via Zeeman Rabi Oscillations

Thanmay S. Menon·Dawson P. Hewatt·Christopher Kiehl·Michaela Ellmeier·Svenja Knappe·Cindy A. Regal
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Abstract

Accurate magnetic field direction sensing in compact platforms is critical in applications spanning magnetic navigation, space science, and biomedical imaging. We demonstrate a single-optical-axis vector optically pumped magnetometer based on Rabi oscillations between Zeeman sublevels driven by a series of resonant radiofrequency (RF) polarization ellipses (PEs). A calibration protocol based on controlled rotations of the DC magnetic field determines the spatial orientation of each PE. We develop a detailed theoretical model describing the angular dependence of the Rabi frequencies, incorporating key systematics including RF Stark shifts and Bloch-Siegert shifts. We also account for an RF-based heading-error systematic affecting Rabi-frequency measurements arising from the nonlinear Zeeman effect. Simultaneous Larmor measurements yield the magnitude of the magnetic field, enabling integrated vector-scalar measurements. The magnetometer achieves deadzone-free vector operation with 80 $μ$rad mean angular accuracy and angular noise densities as low as 8 $μ$rad$/\sqrt{\mathrm{Hz}}$, offering a pathway towards miniaturized sensors without requiring 3D optical access or sensor rotations.

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Thanmay S. Menon, Dawson P. Hewatt, Christopher Kiehl, Michaela Ellmeier, Svenja Knappe, Cindy A. Regal. 2026-03-11. An Accurate Vector Magnetometer via Zeeman Rabi Oscillations. https://arxiv.org/abs/2603.08594

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