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arXiv · 2409.02199

Microwave-free imaging magnetometry with nitrogen-vacancy centers in nanodiamonds at near-zero field

Saravanan Sengottuvel·Omkar Dhungel·Mariusz Mrózek·Arne Wickenbrock·Dmitry Budker·Wojciech Gawlik·Adam M. Wojciechowski
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Abstract

Magnetometry using Nitrogen-Vacancy (NV) color centers in diamond predominantly relies on microwave spectroscopy. However, microwaves may hinder certain studies involving biological systems or thin conductive samples. This work demonstrates a wide-field, microwave-free imaging magnetometer utilizing NV centers in nanodiamonds by exploiting the cross-relaxation feature near zero magnetic fields under ambient conditions without applying microwaves. For this purpose, we measure the center shift, contrast, and linewidth of the zero-field cross-relaxation in 140 nm nanodiamonds drop-cast on a current-carrying conductive pattern while scanning a background magnetic field, achieving a sensitivity of 4.5 $\mathrm{\mu T/\sqrt{Hz}}$. Our work allows for applying the NV zero-field feature in nanodiamonds for magnetic field sensing in the zero and low-field regimes and highlights the potential for microwave-free all-optical wide-field magnetometry based on nanodiamonds.

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Saravanan Sengottuvel, Omkar Dhungel, Mariusz Mrózek, Arne Wickenbrock, Dmitry Budker, Wojciech Gawlik, Adam M. Wojciechowski. 2024-09-03. Microwave-free imaging magnetometry with nitrogen-vacancy centers in nanodiamonds at near-zero field. https://doi.org/10.1103/physrevapplied.23.034001

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