Featured Research

from universities, journals, and other organizations

Lattice of magnetic vortices: Researchers find magnetic skyrmions in atomically thin metal film

Date:
August 3, 2011
Source:
Christian-Albrechts-Universitaet zu Kiel
Summary:
Physicists in Germany have found for the first time a regular lattice of magnetic skyrmions -- cycloidal vortex spin structures of exceptional stability -- on a surface. The researchers discovered the magnetic skyrmions, which consist of 15 atoms, in an atomic layer of iron on the surface of an iridium crystal. This discovery could give new impetus to the area of spintronics.

The tiny cycloidal vortices composed of only approximately 15 atoms form a regular, almost square lattice. In the right section of the illustration the magnetic measurement by spin-polarized scanning tunnelling microscopy is shown as a gray-scale image. The square cutout represents a single skyrmion. The colored cones show the magnetic direction of the individual, hexagonally arranged iron atoms of the metal film.
Credit: M. Menzel, University of Hamburg

Physicists at Hamburg and Kiel University and the Forschungszentrum Jülich have found for the first time a regular lattice of magnetic skyrmions – cycloidal vortex spin structures of exceptional stability – on a surface. This fascinating magnetic structure was discovered experimentally at the University of Hamburg by spin-polarized scanning tunnelling microscopy and imaged on the atomic scale.

Theoreticians at the Christian-Albrechts-Universität zu Kiel and the Forschungszentrum Jülich were able to explain this magnetic state with the help of quantum mechanical calculations performed on supercomputers. As the scientific magazine Nature Physics reports online on July 31, 2011, the researchers discovered the magnetic skyrmions, which consist of 15 atoms, in an atomic layer of iron on the surface of an iridium crystal. This discovery could give new impetus to the area of spintronics.

About 50 years ago the theoretical physicist, Tony Skyrme, studied quantum mechanical field theories and to his surprise found stabile and localized configurations that interact with each other and can arrange themselves in a lattice in the same way as atoms. Due to these properties he identified these vortex-like solutions as elementary particles. These skyrmions named after their discoverer later appeared in many different fields of physics and developed into an important concept. The possible formation of skyrmions in magnetic materials had already been predicted 20 years ago and was also confirmed experimentally in bulk materials.

The magnetic skyrmion lattice discovered in Hamburg occurs in an atomically thin film on a surface. The diameter of the vortices is only a few atoms and is thus at least one order of magnitude smaller than the previously known magnetic skyrmions. As it is often the case chance also played a major role in this discovery. "It is known that iron can sometimes form unusual magnetic structures. Still it was a great surprise when we found this almost square magnetic structure on the nanometer scale which is not really compatible with the hexagonal system of the iron atoms", said Dr. Kirsten von Bergmann, member of the experimental research group headed by Prof. Roland Wiesendanger in Hamburg. The fact "that a sophisticated variation of the experimental setup gives data that can be compiled to yield the complicated magnetic structure" fascinates also Matthias Menzel, a postgraduate student.

In order to understand this intriguing spin structure and the exceptional symmetry breaking between magnetic and atomic order, the theoreticians at the University of Kiel and the Forschungszentrum Jülich had to develop a model for the spin structure and carry out complex quantum mechanical calculations on supercomputers at Jülich. These provided the confirmation that stable magnetic skyrmions form on this metal surface. Professor Stefan Heinze, Head of the research group in Kiel: "With the help of our model we were able to specify the precise spin structure in the iron film and identify it as a skyrmion lattice. The comparison with the experimental data provided the ultimate proof for our discovery."

The interplay of various magnetic interactions is the cause for the occurrence of this complex structure. While the canting of atomic spins with a certain rotational sense is caused by the antisymmetric Dzyaloshinskii-Moriya interaction, the skyrmions found here can only be induced by the so-called four-spin interaction with the participation of four magnetic atoms.

The magnetic skyrmions found open up completely new possibilities for future applications, for example in the field of spintronics, but at the same time raise new questions: How does electric current interact with the skyrmions and can we deliberately move the magnetic vortices in a specific manner?

 


Story Source:

The above story is based on materials provided by Christian-Albrechts-Universitaet zu Kiel. Note: Materials may be edited for content and length.


Journal Reference:

  1. Stefan Heinze, Kirsten von Bergmann, Matthias Menzel, Jens Brede, André Kubetzka, Roland Wiesendanger, Gustav Bihlmayer, Stefan Blügel. Spontaneous atomic-scale magnetic skyrmion lattice in two dimensions. Nature Physics, 2011; DOI: 10.1038/NPHYS2045

Cite This Page:

Christian-Albrechts-Universitaet zu Kiel. "Lattice of magnetic vortices: Researchers find magnetic skyrmions in atomically thin metal film." ScienceDaily. ScienceDaily, 3 August 2011. <www.sciencedaily.com/releases/2011/08/110801094558.htm>.
Christian-Albrechts-Universitaet zu Kiel. (2011, August 3). Lattice of magnetic vortices: Researchers find magnetic skyrmions in atomically thin metal film. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2011/08/110801094558.htm
Christian-Albrechts-Universitaet zu Kiel. "Lattice of magnetic vortices: Researchers find magnetic skyrmions in atomically thin metal film." ScienceDaily. www.sciencedaily.com/releases/2011/08/110801094558.htm (accessed April 23, 2014).

Share This



More Matter & Energy News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) — South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
China Falls for 4x4s at Beijing Auto Show

China Falls for 4x4s at Beijing Auto Show

AFP (Apr. 22, 2014) — The urban 4x4 is the latest must-have for Chinese drivers, whose conversion to the cult of the SUV is the talking point of this year's Beijing auto show. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Lytro Introduces 'Illum,' A Professional Light-Field Camera

Lytro Introduces 'Illum,' A Professional Light-Field Camera

Newsy (Apr. 22, 2014) — The light-field photography engineers at Lytro unveiled their next innovation: a professional DSLR-like camera called "Illum." Video provided by Newsy
Powered by NewsLook.com
3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

TheStreet (Apr. 22, 2014) — Sales of motorcycles have continued to ride back from the depths of hell known as the Great Recession. Excluding scooters, sales of motorcycles increased 3% in 2013. In units, however, at 465,000 sold last year, the total remained about 50% below the peak hit in 2007. Industry leader Harley Davidson’s shareholders have benefited both by the industry recovery and positive headlines emanating from the company. Belus Capital Advisors CEO Brian Sozzi takes you beyond the headlines of the motorcycle maker. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

More Coverage


Discovery of a New Magnetic Order

July 31, 2011 — Physicists have discovered a regular lattice of stable magnetic skyrmions -- radial spiral structures made up of atomic-scale spins -- on a surface instead of in bulk materials. Such tiny formations ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins