Professor Mathias Kläui at the Institute of Physics of Johannes Gutenberg-University Mainz (JGU) has been awarded together with cooperation partners at Forschungszentrum Jülich and Radboud University Nijmegen in the Netherlands a prestigious ERC Synergy Grant. In the “3D MAGiC” project, the partners will explore still largely unknown nanoscale 3D magnetic structures, which show particle-like properties and whose existence has so far only been predicted theoretically. Synergy grants are awarded for groundbreaking projects which, due to their complexity, cannot be carried out alone but only by a team of two to four investigators. The group in Mainz will receive more than EUR 3 million over six years with a total funding of just under EUR 12 million for the consortium.

Questions such as how particles emerge into the world, what their properties are, and how they interact in external fields are central topics in physics. They are relevant in subjects that range from astronomical dimensions, where they apply to stars, exoplanets and black holes in gravitational fields, to the subatomic scales of elementary particles. Between these dimensions are atoms, molecules, and other nanoscale particles such as so-called magnetic topological solitons, which are governed by the laws of quantum mechanics and electromagnetism.

(fltr) Professor Rafal Dunin-Borkowski, Professor Theo Rasing, Professor Stefan Blügel, and Professor Mathias Kläui
photo/©: Mathias Kläui, 3D MAGiC Project

Still puzzling: Three-dimensional magnetic solitons

The topological magnetic solitions that will be studied in the ERC Synergy Grant are magnetic whirls only a few nanometers large that can be present in particular solid state systems and about which little is known today.

“The first magnetic vortices that were detected can be regarded as two-dimensional objects. We are now at a threshold where it will be possible to experimentally study three-dimensional vortex-like structures. One of our goals is to extend our methods of electron holography for this purpose,” explained Professor Rafal Dunin-Borkowski, principal investigator of the project and Director of the Ernst Ruska-Centre and the Peter Grünberg Institute at Forschungszentrum Jülich.

In “3D MAGiC”, the researchers want to investigate particles that may have an even greater potential. Among other things, the focus is on so-called hopfions: “These novel particles can be imagined as twisted or knotted shoelaces. The more loops they contain, the higher the Hopf number,” said Stefan Blügel, Head of the Institute for Advanced Simulation und Director of the Peter Grünberg Institut at Forschungszentrum Jülich.

These objects are interesting for future applications: According to theoretical considerations, the Hopf number can assume many different values, which makes these novel particles highly effective as information carriers. If many such particles are collected in a material, then a large store of information can be created. Their spatial extent makes it possible to cross-link them in a variety of ways via spin waves in all three spatial dimensions – a concept that cannot be realized in two dimensions. For this reason, hopfions may be suitable candidates for innovative approaches in the field of neuromorphic computing, taking inspiration from the human brain, which is very highly connected. Such topics are also currently investigated in the Research Center for Emergent Algorithmic Intelligence at JGU, which was recently founded with funding from the Carl Zeiss Foundation.

ERC project complements the top-level research area TopDyn – Topology and Dynamics

Magnetic heterostructures to host such magnetic solitons will be fabricated in the group of Professor Mathias Kläui at Mainz University. These quasi-particles will then be characterized by highly time-resolved microscopy based on electrons and x-rays. “I am extremely pleased about the possibility to develop this exciting area of research with these excellent colleagues. The major scientific potential of these often topologically non-trivial solitons complements perfectly our research in TopDyn – Topology and Dynamics, which is funded by the state of Rhineland-Palatinate.”

The fourth partner, Professor Theo Rasing of Radboud University in Nijmegen, is a specialist in the ultrafast manipulation and characterization of magnetic nanostructures using laser pulses and will, among other things, investigate how lasers can be used for unconventional computing using 3D nanoscale particles such as hopfions. As an additional partner from outside Europe, Professor Xiaoyan Zhong from Tsinghua University in Beijing, China, is involved in the further development of the characterization methods.

Largest funding scheme for groundbreaking pioneering research

ERC Synergy Grants are the largest funding scheme in terms of awarded funds of up to EUR 10 million, in exceptional cases up to EUR 14 million for six years. In this round, 37 projects were funded based on proposals of two to four principal investigators. The funding is awarded strictly on the basis of scientific excellence of the research topic and the team that has to have already demonstrated outstanding work.

Mathias Kläui studied mathematics and physics at RWTH Aachen University and the University of Cambridge, UK. He did his Ph.D. in Cambridge before a postdoctoral stay at IBM Rüschlikon near Zurich in Switzerland. After stays in Konstanz and in Switzerland he was appointed as full Professor at Johannes Gutenberg University Mainz in 2011. Here he has been Director of the Graduate School of Excellence Materials Science in Mainz since 2012 and Director of TopDyn – Topology and Dynamics since 2019. TopDyn was founded with support from the Research Initiative of the State of Rhineland-Palatinate. In 2014, Kläui became the founding director of the Gutenberg College for Young Researchers (CYR), which supports young researchers at Mainz University.