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arXiv · 2512.03748

Widefield Quantum Sensor for Vector Magnetic Field Imaging of Micromagnetic Structures

Orlando D. Cunha·Filipe Camarneiro·João P. Silva·Hariharan Nhalil·Ariel Zaig·Lior Klein·Jana B. Nieder
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Abstract

Many spintronic, magnetic-memory, and neuromorphic devices rely on spatially varying magnetic fields. Quantitatively imaging these fields with full vector information over extended areas remains a major challenge. Existing probes either offer nanoscale resolution at the cost of slow scanning, or widefield imaging with limited vector sensitivity or material constraints. Quantum sensing with nitrogen-vacancy (NV) centers in diamond promises to bridge this gap, but a practical camera-based vector magnetometry implementation on relevant microstructures has not been demonstrated. Here we adapt a commercial widefield microscope to implement a camera-compatible pulsed optically detected magnetic resonance protocol to reconstruct stray-field vectors from microscale devices. By resolving the Zeeman shifts of the four NV orientations, we reconstruct the stray-field vector generated by microfabricated permalloy structures that host multiple stable remanent states. Our implementation achieves a spatial resolution of $\approx 0.52 ~μ\mathrm{m}$ across an $83~μ\mathrm{m} \times 83~μ\mathrm{m}$ field of view and a peak sensitivity of $ (828 \pm 142)~\mathrm{nT\,Hz^{-1}}$, with acquisition times of only a few minutes. These results establish pulsed widefield NV magnetometry on standard microscopes as a practical and scalable tool for routine vector-resolved imaging of complex magnetic devices.

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Orlando D. Cunha, Filipe Camarneiro, João P. Silva, Hariharan Nhalil, Ariel Zaig, Lior Klein, Jana B. Nieder. 2025-12-03. Widefield Quantum Sensor for Vector Magnetic Field Imaging of Micromagnetic Structures. https://arxiv.org/abs/2512.03748

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