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 Quantum gas turns supersolid
23.04.2019 | Universität Innsbruck

nachricht Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun
18.04.2019 | University of Warwick

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: Quantum gas turns supersolid

Researchers led by Francesca Ferlaino from the University of Innsbruck and the Austrian Academy of Sciences report in Physical Review X on the observation of supersolid behavior in dipolar quantum gases of erbium and dysprosium. In the dysprosium gas these properties are unprecedentedly long-lived. This sets the stage for future investigations into the nature of this exotic phase of matter.

Supersolidity is a paradoxical state where the matter is both crystallized and superfluid. Predicted 50 years ago, such a counter-intuitive phase, featuring...

Im Focus: Explosion on Jupiter-sized star 10 times more powerful than ever seen on our sun

A stellar flare 10 times more powerful than anything seen on our sun has burst from an ultracool star almost the same size as Jupiter

  • Coolest and smallest star to produce a superflare found
  • Star is a tenth of the radius of our Sun
  • Researchers led by University of Warwick could only see...

Im Focus: Quantum simulation more stable than expected

A localization phenomenon boosts the accuracy of solving quantum many-body problems with quantum computers which are otherwise challenging for conventional computers. This brings such digital quantum simulation within reach on quantum devices available today.

Quantum computers promise to solve certain computational problems exponentially faster than any classical machine. “A particularly promising application is the...

Im Focus: Largest, fastest array of microscopic 'traffic cops' for optical communications

The technology could revolutionize how information travels through data centers and artificial intelligence networks

Engineers at the University of California, Berkeley have built a new photonic switch that can control the direction of light passing through optical fibers...

Im Focus: A long-distance relationship in femtoseconds

Physicists observe how electron-hole pairs drift apart at ultrafast speed, but still remain strongly bound.

Modern electronics relies on ultrafast charge motion on ever shorter length scales. Physicists from Regensburg and Gothenburg have now succeeded in resolving a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Fraunhofer FHR at the IEEE Radar Conference 2019 in Boston, USA

09.04.2019 | Event News

 
Latest News

Control 2019: Fraunhofer IPT presents high-speed microscope with intuitive gesture control

24.04.2019 | Trade Fair News

Marine Skin dives deeper for better monitoring

23.04.2019 | Information Technology

Geomagnetic jerks finally reproduced and explained

23.04.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>