Integrated diamond nanostructures for quantum magnetometry

Precise and portable magnetic field sensing presents several potential applications, from national defence to mineral discovery, meteorological surveys and navigation. Current high sensitivity magnetometers involve cryogenic temperatures, vacuums or bulky gas tanks. Diamond magnetometers based on the quantum properties of nitrogen-vacancy centers (NV centers) present an efficient, lightweight and adaptable alternative to current magnetometers, since they work at ambient temperature and pressure. The systems are therefore portable and require minimal power.

While there are many techniques available to measure magnetic field using NV centers, continuous wave Optically Detected Magnetic Resonance (cw-ODMR) is often used for its simplicity of implementation. Measurements are carried out by exciting the NV centers with a green laser and monitoring their red photoluminescence under different microwave excitations. However, the magnetic field sensitivity of these devices is not competitive with the best magnetometers currently available.

The goal of this project is to improve the sensitivity of diamond magnetometers by fabricating microstructures out of the diamond hosting the NV centers. This talk details how these structures focus optical power, resulting in multiple orders of magnitude improvement in magnetic sensitivity. Our approach thus enables practical and competitive applications for diamond-based magnetometers.