Abstract
Nitrogen-vacancy (NV) defect centers in diamond are promising solid-state magnetometers. Single centers allow for high-spatial-resolution field imaging but are limited in their magnetic field sensitivity. Using defect-center ensembles, sensitivity can be scaled with when is the number of defects. In the present work, we use an ensemble of defect centers within an effective sensor volume of for sensing at room temperature. By carefully eliminating noise sources and using high-quality diamonds with large NV concentrations, we demonstrate, for such sensors, a sensitivity scaling as , where is the total measurement time. The associated photon-shot-noise-limited magnetic-field sensitivity for ac signals of is . For a total measurement time of 100 s, we reach a standard deviation of about 100 fT. Further improvements using decoupling sequences and material optimization could lead to sensitivity.
- Received 16 February 2015
DOI:https://doi.org/10.1103/PhysRevX.5.041001
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Published by the American Physical Society
Erratum
Erratum: Subpicotesla Diamond Magnetometry [Phys. Rev. X 5, 041001 (2015)]
Thomas Wolf, Philipp Neumann, Kazuo Nakamura, Hitoshi Sumiya, Takeshi Ohshima, Junichi Isoya, and Jörg Wrachtrup
Phys. Rev. X 13, 029903 (2023)
Popular Summary
Detecting weak magnetic fields is both at the heart of numerous physics disciplines and highly relevant to a wide diversity of applications (e.g., diagnosing neuromagnetic fields or magnetic resonance imaging). There is a wealth of techniques being explored to enable the efficient detection of weak magnetic fields. Here, we use a method based on solid-state spins and demonstrate for the first time that we are able to measure fields as small as 100 fT (given a measurement time of 100 s) with a detector size of only . Our sensor is based on color centers in diamond that carry an electron spin used for the magnetic measurements. The sensitivity of the sensor is achieved via careful preparation of the sample material and the design of new decoupling schemes that eliminate noise sources from the system.
We employ nitrogen-vacancy centers in diamond as solid-state magnetometers. Ensembles of these centers boost the magnetic-field sensitivity, which scales with the square root of the number of centers. We conduct our sensing at room temperature, using a 532-nm pulsed laser to invoke fluorescence, which we measure. This technique is viable because the fluorescence depends on the spin state of the electrons and therefore the local magnetic field (via Zeeman splitting).
We expect that our results will pave the way for more sensitive applications of detecting weak magnetic fields in disciplines ranging from electronics to medical imaging.
