Prof. Ambacher, what would you like to achieve within the framework of the QMag project?

Our goal is to develop quantum magnetometers with which we can image tiny magnetic fields with unprecedented spatial resolution and sensitivity. We want to attain this with two complementary quantum sensor systems that both use a single electron as a “tactile magnet”: for the first quantum magnetometer, we capture an electron by means of an atomic defect found in diamond, for the second we use an alkali atom with a single electron in its outer shell.

The quantized magnetic moment of a localized electron in a diamond crystal is ideally suited for the realization of a scanning probe quantum magnetometer. A sensor system of this kind enables contact-free measurement of current distributions in microelectronic and nanoelectronic circuits.

Due to the magnetic interaction of a metallic material to be measured with the outer electron of the alkali atom, the sensitivity can be further increased with the aid of a second sensor system. In this flagship project, we will also demonstrate quantum sensors based on optically pumped magnetometers and evaluate them for industrial applications in materials testing and process analysis.

What are the application perspectives of the two technological approaches?

A scanning probe quantum magnetometer can measure magnetic fields with the highest spatial resolution at room temperature without contact or destruction. That means that it can be used to determine the manufacturing tolerances of magnetic data storage devices or to detect magnetite in the sense of orientation of bacteria. Due to their extremely high sensitivity, optically pumped magnetometers are particularly well suited for medical analyses, materials characterization, or production monitoring.

What are your tasks as project coordinator?

Since almost every institute will contribute its own technical and technological expertise to the research and development of the two quantum sensors, I make every effort to ensure that the participating researchers, technical experts, and administrative staff are regularly and intensively coordinated. This ensures close and efficient cooperation between the six participating Fraunhofer institutes and the two associated universities. I would also like to ensure that our project is accompanied by creative public relations and customer-oriented marketing.

How do the partners contribute to the success of the project?

Fraunhofer IPM and Fraunhofer IWM, for example, contribute their extensive expertise in optical metrology and the simulation of atomic defects. The University of Stuttgart and the University of Colorado Boulder contribute their great experimental experience in the characterization of quantum sensors based on diamond and alkali atoms. Each of the challenging milestones can only be achieved in a team. The flagship project is being borne by many smart and interesting people with a shared vision: unlocking the innovation potential of quantum sensors for industrial products.

Prof. Ambacher, thank you very much for the interview!

The interview was conducted by Marco Krämer.

About Oliver Ambacher:

Oliver Ambacher received the titles of Diplom-Physiker and Doctor of Natural Sciences at the LMU and TU Munich in 1989 and 1993 with distinction. As a scientific assistant at the Technical University of Munich, he began researching low-dimensional electron systems in GaN-based heterostructures and quantum wells in 1993. After being appointed to lead assistant professor in 2001, one year later he was appointed Professor of Nanotechnology at the TU Ilmenau. In 2002, he was appointed Director of the Institute for Solid State Electronics and in 2004 Director of the Center for Micro- and Nanotechnologies at the TU Ilmenau. Since October 2007, Oliver Ambacher has been a professor at the University of Freiburg and Director of the Fraunhofer Institute for Applied Solid State Physics IAF.