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Single-spin nitrogen-vacancy hybrid magnetometer with enhanced static field sensitivity

Vinaya K. Kavatamane1,*,†, Dewen Duan1,∥, Hadi Zadeh-Haghighi2, Manh-Huong Phan3, and Gopalakrishnan Balasubramanian1,‡,§

  • *Contact author: vinayakumar.kavatamane@ucalgary.ca
  • †Present address: Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
  • ‡Contact author: gopi@xeedq.com
  • §Present address: XeedQ GmbH, Augustusplatz 1–4, 04109 Leipzig, Germany.
  • ∥Present address: School of Physics and Electronic Engineering, Sichuan University of Science and Engineering, Yibin 644005, China.
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Phys. Rev. Applied 26, 044010 – Published 2 October, 2026

DOI: https://doi.org/10.1103/z5x1-9rng

Abstract

Precision sensing and imaging of weak static magnetic fields are crucial for a variety of emerging nanoscale applications. While nitrogen-vacancy (NV) centers in diamond provide exceptional ac magnetic field sensitivity with nanoscale spatial resolution, their sensitivity to static (dc) magnetic fields is fundamentally limited by the short dephasing time (T2*) due to spin-spin interactions. In this work, we present a hybrid sensing approach that integrates a soft ferromagnetic microwire with a single near-surface NV center to amplify its response to external static magnetic fields. This hybrid configuration achieves a dc magnetic field sensitivity of 63  nT/Hz for a single NV center—about 500 times greater than conventional inhomogeneous broadening- or T2*-limited magnetometry, with potential for further enhancement. The compact and highly sensitive nature of this sensor opens new opportunities for quantum sensing applications involving the detection of static or slowly varying magnetic fields across diverse scientific and technological domains.

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Phys. Rev. Applied 26, 044010– Published 2 October, 2026
  • Received 10 March 2026
  • Revised 28 July 2026
  • Accepted 14 September 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Open access publication funded by Max Planck Society.

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