Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

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

12.07.2018

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

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.


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


The new magnetic phase was discovered and studied at the instrument SANS-1 of the research neutron source Heinz Maier-Leibnitz (FRM II). Alfonso Chacon and Dr. Mühlbauer adjust the detector.

Wenzel Schürmann / TUM

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

Originalpublikation:

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

Kim-Astrid Magister | idw - Informationsdienst Wissenschaft
Further information:
http://www.tu-dresden.de

More articles from Physics and Astronomy:

nachricht Underlying mechanism discovered for magnetic effect in superconducting spintronics
11.07.2018 | American Institute of Physics

nachricht PPPL diagnostic is key to world record of German fusion experiment
10.07.2018 | DOE/Princeton Plasma Physics Laboratory

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

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

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

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...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

Im Focus: Probing nobelium with laser light

Sizes and shapes of nuclei with more than 100 protons were so far experimentally inaccessible. Laser spectroscopy is an established technique in measuring fundamental properties of exotic atoms and their nuclei. For the first time, this technique was now extended to precisely measure the optical excitation of atomic levels in the atomic shell of three isotopes of the heavy element nobelium, which contain 102 protons in their nuclei and do not occur naturally. This was reported by an international team lead by scientists from GSI Helmholtzzentrum für Schwerionenforschung.

Nuclei of heavy elements can be produced at minute quantities of a few atoms per second in fusion reactions using powerful particle accelerators. The obtained...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

Nanotechnology to fight cancer: From diagnosis to therapy

28.06.2018 | Event News

 
Latest News

New computational method for drug discovery

12.07.2018 | Life Sciences

Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture

12.07.2018 | Agricultural and Forestry Science

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

12.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>