Structured-Light Magnetometry in a Coherently Controlled Atomic Medium

Abstract:A structured-light-based approach to magneto-optical rotation (MOR) magnetometry is proposed, in which magnetically induced polarization rotation is converted into a directly observable spatial displacement. A radially polarized Laguerre--Gaussian beam propagating through cold $^{87}\mathrm{Rb}$ atoms in the presence of a longitudinal magnetic field experiences circular birefringence, which induces a relative phase shift between the $\sigma_+$ and $\sigma_-$ polarization components. This phase shift manifests itself as the angular rotation of a petal-shaped interference pattern, enabling the MOR angle to be determined directly from the spatial intensity distribution. Unlike conventional MOR detection techniques based on balanced polarimetry or Stokes-parameter reconstruction, the proposed method requires only a fixed-axis polarization projection and avoids computationally intensive polarization analysis. By translating polarization rotation into a topology-dependent spatial observable, the scheme enables direct and spatially resolved magnetic-field measurements. Furthermore, the use of electromagnetically induced transparency (EIT) allows low-loss operation while preserving high sensitivity. These characteristics make the proposed technique a promising platform for optical magnetometry and structured-light-based quantum sensing.

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

arXiv:2603.25781 [physics.atom-ph]

(or arXiv:2603.25781v3 [physics.atom-ph] for this version)

https://doi.org/10.48550/arXiv.2603.25781 Focus to learn more arXiv-issued DOI via DataCite

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