New interaction between light and matter discovered at BESSY II
A bundled soft X-ray beam with a diameter of less than 50 nanometers writes numerous magnetic vortices, which together form the term "MPI-IS". © Alejandro Posada, Felix Groß/MPI-IS
A German-Chinese team led by Gisela Schütz from the MPI for Intelligent Systems has discovered a new interaction between light and matter at BESSY II. They succeeded in creating nanometer-fine magnetic vortices in a magnetic layer. These are so-called skyrmions, and candidates for future information technologies.
Skyrmions are 100 nanometre small three-dimensional structures that occur in magnetic materials. They resemble small coils: atomic elementary magnets - so-called spins - which are arranged in closed vortex structures. Skyrmions are topologically protected, i.e. their shape is unchangeable, and are therefore considered energy-efficient data storage devices.
Soft x-rays at BESSY II
In a series of experiments on the MAXYMUS beamline of BESSY II, the researchers have now shown that a bundled soft X-ray beam with a diameter of less than 50 nanometres can generate a magnetic vortex of 100 nanometres. In order to make the skyrmions visible, the researchers use the MAXYMUS scanning transmission X-ray microscope. This is a high-resolution X-ray microscope, weighing 1.8 tons, located at BESSY II.
Serendipitous discovery
This discovery was made by chance, as this type of interaction between light and matter was previously completely unknown. "We don't know how light writes matter," says Dr. Joachim Gräfe, head of the research group Nanomagnonics and Magnetization Dynamics at MPI-IS. He is one of the main authors of the study, which was published in Nature communications in February. "We can describe certain properties phenomenologically. We know that it has to do with the X-ray beam. It's not just an energy input like heat that writes the Skyrmion. It's really a resonant effect: we can directly excite the atoms responsible for magnetism." This enabled him and his team to write "MPI-IS" (see figure).
Outlook: Future Spintronics
The results are particularly relevant for the development and production of so-called spintronic data carriers, which store information in skyrmions. They are considered to be energy-efficient and less susceptible to interference. However, this development can only take its course if skyrmions can be created precisely and with a perfect fit - and this has now become possible for the first time. "Our goal is for X-rays to serve as a tool for determining or writing the arrangement of magnetic structures in the future."
- Key technology for a future without fossil fuelsIn June and July 2025, catalyst researcher Nico Fischer spent some time at HZB. It was his sabbatical, he was relieved of his duties as Director of the Catalysis Institute in Cape Town for several months and was able to focus on research only. His institute is collaborating with HZB on two projects that aim to develop environmentally friendly alternatives using innovative catalyst technologies. The questions were asked by Antonia Rötger, HZB.
- Iridium-free catalysts for acid water electrolysis investigatedHydrogen will play an important role, both as a fuel and as a raw material for industry. However, in order to produce relevant quantities of hydrogen, water electrolysis must become feasible on a multi-gigawatt scale. One bottleneck is the catalysts required, with iridium in particular being an extremely rare element. An international collaboration has therefore investigated iridium-free catalysts for acidic water electrolysis based on the element cobalt. Through investigations with various methods, among them experiments at the LiXEdrom at the BESSY II X-ray source in Berlin, they were able to elucidate processes that take place during water electrolysis in a cobalt-iron-lead oxide material as the anode. The study is published in Nature Energy.
- Scrolls from Buddhist shrine virtually unrolled at BESSY IIThe Mongolian collection of the Ethnological Museum of the National Museums in Berlin contains a unique Gungervaa shrine. Among the objects found inside were three tiny scrolls, wrapped in silk. Using 3D X-ray tomography, a team at HZB was able to create a digital copy of one of the scrolls. With a mathematical method the scroll could be virtually unrolled to reveal the scripture on the strip. This method is also used in battery research.