Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Magnetic monopoles erase data

03.06.2013
Efficient and long-lived storage of information in magnetic vortices

A physical particle postulated 80 years ago, could provide a decisive step toward the realization of novel, highly efficient data storage devices. Scientists at the Technische Universitaet Muenchen (TUM), the Technische Universitaet Dresden and the University of Cologne found that with magnetic monopoles in magnetic vortices, called skyrmions, information can be written and erased.


Depiction of the merging of two magnetic vortices, so-called skyrmions, in the magnetic structure of a material. The point at the which the vortices merge displays the properties of an emergent magnetic monopole. When the monopole moves along the direction of the vortices a skyrmion is created or destroyed (Picture: Ch. Schütte/University of Cologne)


A grid of magnetic vortex structures
(Picture: TUM)

Iron filings strewn on a sheet of paper trace the field lines of a bar magnet below the paper, thereby showing the magnet's north and south poles. No matter how often it is split, the bar magnet always forms a north and a south pole. However, in the early 1930s physicist Paul A. M. Dirac postulated a particle that should, as the magnetic counterpart of the electron, possess only one of the two poles, and should carry just one magnetic elementary charge.

Looking for a simple way to study the magnetic vortices, researchers associated with TUM physicist Prof. Christian Pfleiderer collaborated with Prof. Lukas Eng's group at the Technische Universitaet Dresden, which has a magnetic force microscope. When they scanned the surface of the materials with this microscope, they not only observed the vortices for the first time, but also found that neighboring skyrmions merge with one another.

Computer simulations of Prof. Achim Rosch's group at Cologne, together with experiments at the research neutron source FRM II at TUM, showed that magnetic monopoles were at work here, drawing the vortices together like a zipper.

Compact and long-lived data storage

An important future application of the magnetic eddies could be extremely compact and long-lived storage media. Whereas one needs around a million atoms to store one bit in a modern hard disk, the smallest known skyrmions in magnetic materials consist of only 15 atoms.

At the same time moving such skyrmions requires 100,000 times less power than moving memory bits in devices based on conventional magnetic materials, in order to process information such a precisely controlled manner. Perhaps the most interesting characteristic of skyrmions, however, is that they are especially stable, like a knot in a string.
The magnetic vortex structures were discovered in 2009 through neutron scattering experiments on manganese-silicon in the research neutron source FRM II, conducted by a team around Christian Pfleiderer and Achim Rosch. Since then this area of research has attracted intense interest and made rapid progress worldwide. "Whereas initially the experiments required extremely low temperatures, today we also know materials in which skyrmions exist at room temperature," says Christian Pfleiderer, Professor for Magnetic Materials at the Technische Universitaet Muenchen.

"With the magnetic force microscopy, we finally have a method at hand that allows us for the first time to observe skyrmions in systems that are relevant for applications. This is a decisive step in the direction of a real technical use."

The work was funded by the European Research Council, the German Research Foundation, (DFG), and the Australian Research Council, as well as the TUM Graduate School and the Bonn-Cologne Graduate School.

Publication:
Unwinding of a Skyrmion Lattice by Magnetic Monopoles, 
P. Milde, D. Köhler, J. Seidel, L. M. Eng, A. Bauer, A. Chacon, J. Kindervater, S. Mühlbauer, C. Pfleiderer, S. Buhrandt, C. Schütte, A. Rosch, 
Science, Advanced online publication, 31 May 2013, DOI: after end of embargo
Contact:
Prof. Dr. Christian Pfleiderer
Technische Universität München

Physik-Department


T: +49.89.289-14720

E: christian.pfleiderer@frm2.tum.de

Patrick Regan | EurekAlert!
Further information:
http://www.e21.ph.tum.de

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: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>