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arXiv · 1212.1495

Absolute magnetometry based on quantum beats in diamond nitrogen-vacancy centers

Kejie Fang·Victor M. Acosta·Charles Santori·Zhihong Huang·Kohei M. Itoh·Hideyuki Watanabe·Shinichi Shikata·Raymond G. Beausoleil
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Abstract

We demonstrate an absolute magnetometer immune to temperature fluctuation and strain inhomogeneity, based on quantum beats in the ground state of nitrogen-vacancy centers in diamond. We apply this technique to measure low-frequency magnetic field noise using a single nitrogen-vacancy center located within 500 nm of the surface of an isotopically-pure (99.99% C12) diamond. The photon-shot-noise limited sensitivity achieves 38 nT/Hz^1/2 for 4.45 s acquisition time, a factor of 2^1/2 better than the implementation which uses only two spin levels. For long acquisition times (>10 s), we realize up to a factor of 15 improvement in magnetic sensitivity, which demonstrates the robustness of our technique against thermal drifts. Applying our technique to nitrogen-vacancy center ensembles, we eliminate dephasing from longitudinal strain inhomogeneity, resulting in a factor of 2.3 improvement in sensitivity.

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Kejie Fang, Victor M. Acosta, Charles Santori, Zhihong Huang, Kohei M. Itoh, Hideyuki Watanabe, Shinichi Shikata, Raymond G. Beausoleil. 2012-12-06. Absolute magnetometry based on quantum beats in diamond nitrogen-vacancy centers. https://doi.org/10.1103/physrevlett.110.130802

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