. 24/7 Space News .
Extremely small magnetic nanostructures with invisibility cloak imaged
by Staff Writers
Berlin, Germany (SPX) Oct 19, 2018

In the future, a magnetic skyrmion could encode a "1" in data storage. The skyrmion is made up by the specific arrangement of the magnetic moments of neighboring atoms, represented by arrows in the images. Shown on the right is a skyrmion where neighboring atoms have approximately opposite magnetization, hence cloaking the resulting net magnetic stray field. In this way, smaller diameter skyrmions are stable. Physicists talk about "antiferromagnetic" (AFM) rather than "ferromagnetic" (FM) order between neighboring moments .

In novel concepts of magnetic data storage, it is intended to send small magnetic bits back and forth in a chip structure, store them densely packed and read them out later. The magnetic stray field generates problems when trying to generate particularly tiny bits.

Now, researchers at the Max Born Institute (MBI), the Massachusetts Institute of Technology (MIT) and DESY were able to put an "invisibility cloak" over the magnetic structures. In this fashion, the magnetic stray field can be reduced in a fashion allowing for small yet mobile bits. The results were published in Nature Nanotechnology.

For physicists, magnetism is intimately coupled to rotating motion of electrons in atoms. Orbiting around the atomic nucleus as well as around their own axis, electrons generate the magnetic moment of the atom. The magnetic stray field associated with that magnetic moment is the property we know from e.g. a bar magnet we use to fix notes on pinboard.

It is also the magnetic stray field that is used to read the information from a magnetic hard disk drive. In today's hard disks, a single magnetic bit has a size of about 15 x 45 nanometer, about of those would fit on a stamp.

One vision for a novel concept to store data magnetically is to send the magnetic bits back and forth in a memory chip via current pulses, in order to store them at a suitable place in the chip and retrieve them later.

Here, the magnetic stray field is a bit of a curse, as it prevents that the bits can be made smaller for even denser packing of the information. On the other hand, the magnetic moment underlying the stray field is required to be able to move the structures around.

The researchers were now able to put an "invisibility cloak" on the magnetic nanostructures and to observe, how small and how fast such structures can get. To this end, different atomic elements with opposite rotation of the electrons were combined in one material. In this way, the magnetic stray field can be reduced or even completely cancelled - the individual atoms, however, still carry a magnetic moment but together appear cloaked.

In spite of this cloaking, the scientists were able to image the tiny structures. Via x-ray holography, they were able to selectively make only the magnetic moments of one of the constituent elements visible - in this way an image can be recorded in spite of the invisibility cloak.

It became apparent, that fine tuning of the strength of the invisibility cloak allows to simultaneously meet two goals which are of importance for potential applications in data storage. "In our images, we see very small, disk-like magnetic structures", says Dr. Bastian Pfau from MBI. "The smallest structures we observed had a diameter of only 10 nanometer."

The information density of today's hard disk drives could be significantly increased, if such structures could be used to encode the data. Furthermore, in additional measurements the researchers realized that suitably cloaked bits can be moved particularly fast by short current pulses - an important property for actual use in a memory device. A velocity higher than 1 kilometer per second was reached in the MIT laboratory.

"This is possible as a consequence of quantum physics", explains Prof. Stefan Eisebitt from MBI. "The contribution of the electron's orbit around the nucleus to the magnetic moment is only half as large as the contribution of the electron's spin around its own axis."

When combining different atom types with different direction and strength of this rotation in one material, one can cancel the total rotation - physicists talk about the total angular momentum - of the system, while still retaining a small magnetic moment. As the angular momentum leads to a drag when moving the structures via current pulses, this approach allows for high speed motion.

Hence, if the strength of the invisibility cloak is adjusted just right, both small size and high speed of the magnetic bit structures can be achieved - an interesting prospect for novel magnetic data storage concepts.

Research paper

Related Links
Forschungsverbund Berlin
Space Technology News - Applications and Research

Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly

paypal only
SpaceDaily Contributor
$5 Billed Once

credit card or paypal

High entropy alloys hold the key to studying dislocation avalanches in metals
Chicago IL (SPX) Oct 18, 2018
Mechanical structures are only as sound as the materials from which they are made. For decades researchers have studied materials from these structures to see why and how they fail. Before catastrophic failure, there are individual cracks or dislocations that form, which are signals that a structure may be weakening. While researchers have studied individual dislocations in the past, a team from the University of Illinois at Urbana-Champaign, the University of Tennessee, and Oak Ridge National Lab ... read more

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Smell and stress sensors a smash at Tokyo tech fair

Escape capsule with Soyuz MS-10 crew hit ground 5 times before stopping

'Concrete block on your chest': astronauts recount failed space launch

Russian cosmonaut reveals what ISS crew truly fears

Jeff Bezos to invest more than $1 bn in Blue Origin in 2019

Russian Space Corp gets telemetry data, video to probe Soyuz failure

NASA continues fall series of RS-25 engine tests

Advanced Rockets Corp appoints first Chief Operation Officer

Scientists to debate landing site for next Mars rover

Efforts to communicate with Opportunity continue

Painting cars for Mars

Novel Technique Quickly Maps Young Ice Deposits and Formations on Mars

China launches Centispace-1-s1 satellite

China tests propulsion system of space station's lab capsules

China unveils Chang'e-4 rover to explore Moon's far side

China's SatCom launch marketing not limited to business interest

Source reveals timing of OneWeb satellites' debut launch on Soyuz

French Space Agency opens new office in the UAE

Maxar's SSL Continues Positive Momentum in Growing US Government Pipeline

Space techpreneur to set up over $100m venture unit

ELTA nabs $55M contract for combat aircraft radars for Asian customer

Blue phosphorus mapped and measured for the first time

High entropy alloys hold the key to studying dislocation avalanches in metals

Russian firm mulls sending duplicate 3D Bioprinter to ISS after Soyuz failure

Life-long space buff and Western graduate student discovers exoplanet

How the seeds of planets take shape

NASA should expand search for life in the universe: NAS Report

The stuff that planets are made of

Icy warning for space missions to Jupiter's moon

New Horizons sets up for New Year's flyby of Ultima Thule

Hunt for Planet X reveals the Goblin, a faraway dwarf planet

While seeking Planet X, astronomers find a distant solar system object

The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.