Producing highly sensitive quantum magnetometers

 

Diamond-based quantum magnetometers have been created by the Fraunhofer Institute for AppliedSolid State Physics (IAF).

 

The Fraunhofer IAF's quantum magnetometers, which use diamonds to detect magnetic fields with a spatial resolution of a few nanometres down to single electron and nuclear spins, can detect magnetic fields with a spatial resolution of a few nanometres. Diamond quantum magnetometers work at room temperature due to their physical qualities, making them suited for industrial applications. The research institute will present two interesting initiatives at this year's LASER World of PHOTONICS.

 

Magnetometers are now only appropriate for limited industrial usage because their operation is complicated and, in some situations, only practicable with high cooling. Furthermore, for many applications, their spatial resolution is too poor or sensitive.

 

As a result, in the Quantum Magnetometry project (QMag), Fraunhofer researchers from six different institutes collaborated to build sensors that can image small magnetic fields with exceptional spatial resolution, sensitivity, and at room temperature. The Fraunhofer lighthouse project's purpose is to bring quantum magnetometry out of the realm of academic research and into real-world applications. Quantum magnetometers for industrial usage in nanoelectronics, chemical analysis, and materials testing are expected to be developed by the project partners by 2024.

 

Diamond quantum magnetometers

 

The researchers working on the QMag project are putting two separate systems to the test, both of which are based on the same physical measurement principles and procedures but are targeted at different applications: To begin, the researchers are working on an image scanning probe magnetometer based on diamond nitrogen vacancy (NV) centres for precise measurements of nano electronic circuits. Second, they are developing measuring systems for material testing and process analytics based on ultra-sensitive optically pumped magnetometers (OPMs).

"In the first half of the project, we were able to achieve significant progress in the creation and optimization of diamond sensor tips for scanning probe magnetometers," said Dr. Ralf Ostendorf, Project Coordinator at QMag. This pertains to the production of high-quality diamonds as well as the targeted generation and placement of NV centres in diamond tips. The researchers have also created tiny lenses and synthesised magnetic nanoparticles that are included into the diamond tips to improve their precision and efficiency.

 

Measuring the smallest magnetic fields

Fraunhofer IAF's second research project in the field of quantum magnetometry is aimed at medical diagnostic applications:

 

A research team is examining the construction of an exceedingly sensitive sensor that can measure the weak magnetic fields of the heart and brain functions of the human body in the project titled 'NV-doped CVD diamond for ultra-sensitive laser threshold magnetometry (DiLaMag).' This method could be used to diagnose diseases early on.

 

Dr. Jan Jeske, DiLaMag Project Leader, stated, "Our goal is to build an extraordinarily sensitive magnetic field sensor that works at room temperature as well as in existing background fields and is thus realistic for clinical use."