Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

A "skyrmion lattice": a lattice of magnetic vortices - so-called skyrmions --exists also at low temperatures in the chiral magnet The arrows represent the direction of the local magnetization. Markus Garst / TU Dresden

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar structures can be observed in magnetic materials. Magnetic whirls are formed when the magnetic moments are aligned in a circular fashion. These so-called skyrmions are not just interesting for basic research — because of their stability and their tiny dimensions they could prove crucial for the development of future magnetic storage.

For these reasons they are currently at the center of a large body of research. One of the key questions is about when and how they occur. A team of researchers from Technical University of Munich (TUM), Technical University of Dresden and the University of Cologne has shown for the first time, that magnetic skyrmions can form due to different mechanisms in separate phases in the same material. Their discovery in the chiral magnet Cu2OSeO3 near absolute zero temperature (-273.15 °C) is published in the scientific journal Nature Physics.

Tiny magnetic structures for compact magnetic storage?

“Skyrmions usually exist in a single thermodynamic parameter range, that is, a certain range of temperature and magnetic or electric field strength. Indeed, this is the case for all the materials in which skyrmions have been found so far,” explains physicist Christian Pfleiderer of TUM, who led this research study.

“This imposes a constraint for the creation and technical use of skyrmions, since they are only stable as long as one finds and abides to the exact physical parameters required. Now, in a single material we have found two different skyrmion phases, with two different sets of parameters. Previously it was thought that the new mechanism is very weak. But now it turns out, that there are many more possibilities to create and control skyrmions than we have thought.”

Second skyrmion phase at very low temperatures

Alfonso Chacon discovered the new phase, when he studied the metastable properties of an already known skyrmion phase at the research neutron source of TUM. He explains: “These metastable properties interests us, because this way we can learn about the related energies and the stability of skyrmions. This helps us to understand the mechanism of their formation and how they are destroyed. While we performed these measurements I discovered that something very unexpected and odd was going on.”

“At low temperatures quantum effects play an increasingly larger role”, explains Dr. Markus Garst from the Institute of Theoretical Physics at the Technical University of Dresden. “These influence also the physical properties of the magnetic skyrmions. The new findings allow to study quantum skyrmions in magnets in detail.”

“We have been working on skyrmions for more than a decade and for one and a half years at the current project and have a very successful collaboration among the groups,” says Markus Garst. “The colleagues from Munich made their observations with neutron scattering experiments, that allow to visualize magnetic structures. In collaboration with Lukas Heinen and Achim Rosch from Cologne we were able to explain the experimental results.” This scientific discovery was only possible, because of the close collaboration between both experimental and theoretical physicists.

The discovery and study of this magnetic phase took place at the small angle neutron scattering experiment SANS-1 at the Maier Leibnitz Zentrum at the Research Neutron Source Heinz Maier-Leibnitz (FRM II) of TUM.
The research was funded by the German Research Foundation (DFG) in the frame of the Collaborative Research Centres SFB 1143 “Correlated Magnetism: From Frustration To Topology” and SFB 1238 “Control and Dynamics of Quantum Materials” as well as the TRR80 “From Electronic Correlations to Functionality”. The European Union supported the project with the ERC-Grant TOPFIT and the TUM Graduate School supported some of the authors.

Media inquiries:
PD Dr. Markus Garst
Institute of Theoretical Physics
Technische Universität Dresden
Tel.: +49 (0) 351 463 32847
E-Mail: markus.garst@tu-dresden.de

Prof. Dr. Christian Pfleiderer
Chair for Topology of Correlated Systems
Physik-Department
Technische Universität München
Tel.: +49 (0) 89 289-14720
E-Mail: christian.pfleiderer@tum.de

Observation of two independent skyrmion phases in a chiral magnetic material
A. Chacon, L. Heinen, M. Halder, A. Bauer, W. Simeth, S. Mühlbauer, H. Berger, M. Garst, A. Rosch and C. Pfleiderer
Nature Physics (2018)
DOI: 10.1038/s41567-018-0184-y

Media Contact

Kim-Astrid Magister idw - Informationsdienst Wissenschaft

Weitere Informationen:

http://www.tu-dresden.de

Alle Nachrichten aus der Kategorie: Physics and Astronomy

This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.

innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.

Zurück zur Startseite

Kommentare (0)

Schreib Kommentar

Neueste Beiträge

Cyanobacteria: Small Candidates …

… as Great Hopes for Medicine and Biotechnology In the coming years, scientists at the Chair of Technical Biochemistry at TU Dresden will work on the genomic investigation of previously…

Do the twist: Making two-dimensional quantum materials using curved surfaces

Scientists at the University of Wisconsin-Madison have discovered a way to control the growth of twisting, microscopic spirals of materials just one atom thick. The continuously twisting stacks of two-dimensional…

Big-hearted corvids

Social life as a driving factor of birds’ generosity. Ravens, crows, magpies and their relatives are known for their exceptional intelligence, which allows them to solve complex problems, use tools…

By continuing to use the site, you agree to the use of cookies. more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close