Microwave-free magnetometry with nitrogen-vacancy centers in diamond

TL;DR

This paper introduces a microwave-free magnetometry technique using nitrogen-vacancy centers in diamond, enabling magnetic field measurements with high sensitivity suitable for remote sensing and applications near conductive materials.

Contribution

It demonstrates a novel microwave-free approach to NV center magnetometry based on level anti-crossing, achieving a noise floor of 6 nT/√Hz.

Findings

Achieved a noise floor of 6 nT/√Hz in magnetic field measurement.

Demonstrated the technique's suitability for remote sensing and proximity to conductive materials.

Provided a method that does not require microwaves, simplifying the setup.

Abstract

We use magnetic-field-dependent features in the photoluminescence of negatively charged nitrogen-vacancy centers to measure magnetic fields without the use of microwaves. In particular, we present a magnetometer based on the level anti-crossing in the triplet ground state at 102.4 mT with a demonstrated noise floor of 6 nT/$\sqrt{\text{Hz}}$, limited by the intensity noise of the laser and the performance of the background-field power supply. The technique presented here can be useful in applications where the sensor is placed closed to conductive materials, e.g. magnetic induction tomography or magnetic field mapping, and in remote-sensing applications since principally no electrical access is needed.