Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers use skyrmions to store information

09.08.2013
On the cover of "Science": Magnetic nano-knots for data storage

Physicists of the University of Hamburg, Germany, managed for the first time to individually write and delete single skyrmions, a knot-like magnetic entity. Such vortex-shaped magnetic structures exhibit unique properties which make them promising candidates for future data storage devices.


Figure 1: A skyrmion can be imagined as a two-dimensional magnetic knot, in which the magnetic moments are rotating with unique rotational sense by 360° within a plane. The image shows data from a spin-resolved scanning tunneling microscopy experiment together with a sketch of the sample magnetization.

Group of R. Wiesendanger, University of Hamburg

Skyrmions have been in the focus of active research for the last years; however, up to now these states have been merely investigated, a controlled manipulation has not been achieved. Now this has been realized by scientists from the group of Prof. Roland Wiesendanger in Hamburg, Germany: as Science Magazine reports online on 08th of August 2013, the creation and annihilation of single skyrmions, corresponding to writing and deleting of information on a storage medium, has been demonstrated by these researchers.

This work solves one of the longstanding technical problems concerning the future use of skyrmions in information technology.

Future electronic devices are expected to become smaller while increasing their data storage capacities at the same time. This will soon bring classical storage technologies to their physical limits. In conventional memory devices used up to now, magnetic bits consist of many atoms with their magnetic moments aligned parallel to each other like bar magnets. Pointing in defined directions, they can represent the values “1” and “0” which are the basis for information technology. With the continuing miniaturization, the interaction between neighboring bits increases due to magnetic stray fields which can lead to loss of data. In addition, small magnetic bits are less stable against thermal fluctuations which is also called the superparamagnetic limit.

Using more “robust” magnetic structures like skyrmions could be a way out of this technological dead end. These structures can be imagined as a two-dimensional knot in which the magnetic moments are rotating about 360° in a plane with a unique rotational sense (see Fig. 1). These particle-like magnetic knots can be assigned a kind of charge, the topological charge. With this it is possible to assign the bit states “1” and “0” to the existence or non-existence of a skyrmion.

A clever choice of temperature and external magnetic field enabled the scientists of the group of Prof. Roland Wiesendanger to prepare and manipulate single magnetic skyrmions for the first time. They used a two atomic layer thick film of palladium and iron on an iridium crystal. In an external magnetic field this sample exhibits single localized skyrmions with a diameter of a few nanometers that can be imaged in a spin-polarized scanning tunneling microscope. Using small currents from the tip of the microscope these skyrmions can be written and deleted. For the creation the previously parallel magnetic moments are twisted to form a knot-like magnetic state, and for the deletion this knot is unwound again.

„We finally found a magnetic system in which we can locally switch between ordinary ferromagnetic order and a complex spin configuration“, says Dr. Kirsten von Bergmann, senior scientist in the Wiesendanger group. As published in the current issue of the Science Magazine, four skyrmions were specifically addressed and could be created and annihilated (Fig. 1). “We transferred the idea of tying a knot to memorize something to the field of storage technology so we can now store data in a two-dimensional magnetic knot”, explains Ph.D. student Niklas Romming.

Whether skyrmions will be used as data storage units in our computers, tablets, or smartphones, is not foreseeable. The experimentally accomplished writing and deleting of skyrmions, however, has demonstrated the feasibility of this technology and paved the way towards a realization of such devices.

Original publication:
Writing and Deleting Single Magnetic Skyrmions,
N. Romming, C. Hanneken, M. Menzel, J. E. Bickel, B. Wolter, K. von Bergmann, A. Kubetzka, and R. Wiesendanger

Science (2013).

Further questions:
Dipl.-Chem. Heiko Fuchs
DFG-Collaborative Research Center 668 and
ERC Advanced Grant Group "FURORE"
Institute of Applied Physics
University of Hamburg
Jungiusstr. 9a
20355 Hamburg, Germany
Phone: +49 - 40 - 42838 - 69 59
e-mail: hfuchs@physnet.uni-hamburg.de

Heiko Fuchs | idw
Further information:
http://www.nanocience.de
http://www.sfb668.de
http://www.nanoscience.de/furore

More articles from Physics and Astronomy:

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

nachricht Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | 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

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>