The Fraunhofer Institute for Applied Solid State Physics (IAF) has developed quantum magnetometers based on diamonds.
The quantum magnetometers, developed by the Fraunhofer IAF by utilising diamonds, have the ability to detect magnetic fields with a spatial resolution of a few nanometres down to single electron and nuclear spins. Due to the physical material properties, diamond quantum magnetometers operate at room temperature, which is ideal for industrial applications. At this year’s LASER World of PHOTONICS, the research institute is going to present two promising projects.
Currently, magnetometers are only suitable for industrial use to a limited extent, as their operation is complex and, in some cases, only possible with extreme cooling. In addition, their spatial resolution is too low or sensitive for many applications.
As a result, Fraunhofer researchers from six different institutes have collaborated in the Quantum Magnetometry project (QMag) to develop sensors that can image tiny magnetic fields with unprecedented spatial resolution, sensitivity and at room temperature. The goal of the Fraunhofer lighthouse project is to transfer quantum magnetometry from the university research environment to concrete industrial applications. By 2024, the project partners plan to realise quantum magnetometers for industrial use in nanoelectronics, chemical analysis and materials testing.
Diamond quantum magnetometers
In the QMag project, the researchers are testing two different systems that are based on the same physical measurement principles and methods, but are aimed different applications: Firstly, the researchers are developing an imaging scanning probe magnetometer based on nitrogen vacancy (NV) centres in diamonds for precise measurements of nano electronic circuits. Secondly, they are realising measurement systems based on ultra-sensitive optically pumped magnetometers (OPMs) for applications in material testing and process analytics.
“With regard to the scanning probe magnetometers, we were able to make great progress in the development and optimisation of diamond sensor tips in the first half of the project,” explained Dr Ralf Ostendorf, Project Coordinator at QMag. This concerns both the growth of high-quality diamond and the targeted generation and placement of NV centres in the diamond tips. In addition, the researchers have developed micro lenses as well as synthesised magnetic nanoparticles that are introduced into the diamond tips to further optimise their accuracy and efficiency.
Measuring the smallest magnetic fields
The second research project presented by Fraunhofer IAF in the field of quantum magnetometry aims at applications in medical diagnostics:
In the project labelled ‘NV-doped CVD diamond for ultra-sensitive laser threshold magnetometry (DiLaMag)’, a research team is analysing the development of an extremely sensitive sensor that can measure the weak magnetic fields of the heart and brain activities of the human body. This could be employed to detect diseases at an early stage.
“Our goal is to develop an extremely sensitive magnetic field sensor that works at room temperature as well as in existing background fields and is thus practicable for clinical implementation,” commented Dr Jan Jeske, DiLaMag Project Leader.
LASER World of PHOTONICS 2022
At this year’s (2022) LASER World of PHOTONICS trade fair, there will be an exhibition area dedicated to quantum technologies for the first time: In the World of Quantum (Hall A4), the participating Fraunhofer institutes IAF, IPM and IWM will present their project QMag. The joint exhibit demonstrates materials testing with OPMs.
Fraunhofer IAF will also present its research work in the field of diamond growth as well as NV-doped diamond and demonstrate the basic principle of measurement with NV diamonds.