Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stable magnetic bit of three atoms

21.09.2017

As reported today in the journal Nature Communications a team of experimentalists and theoreticians of the University of Hamburg in cooperation with the Forschungszentrum Jülich and the Radboud University in Nijmegen have experimentally realized a ferromagnetic particle composed of only three iron atoms which can serve as a bit for the magnetic storage of information. By particular electronic interactions of the bit with the conductive substrate it is positioned on, the information the bit carries can be processed in an unusual, so called non-collinear, way, which could add new functionality to future elements of information technology.

A reoccurring challenge in storage technology is the continuing demand for smaller “bits”, which is the fundamental storage unit. In magnetic memories this information is stored in the magnetization of small magnets. The need to store more and more information in a smaller and smaller area therefore involves the question of how small we can make a magnet which still keeps its magnetization for a prolonged period of time such that the information is not lost.


Illustration of the constructed magnetic bit composed of only three iron atoms on a platinum substrate

Recently, extensive research in this direction has approached the ultimate limit of storing information in individual atoms. A particular challenge for the use of such small storage elements was the destabilization of their magnetization by the interaction with the electrons of the substrate they are positioned on. Consequently, the prevalent approach in order to stabilize the magnetization was to strongly decouple the magnetic bit from the substrate electrons by the use of insulating layers.

However, this route entails the problem that the processing of the information the bit carries for computational purposes, which is done via exactly those substrate electrons, is rather difficult to achieve. To this end, a bit made of a few atoms which are positioned directly on a conductive substrate is highly desirable.

A team of experimentalists and theoreticians of the University of Hamburg in cooperation with the Forschungszentrum Jülich and the Radboud University in Nijmegen have now experimentally realized such a bit. The bit was constructed by using the magnetic tip of a scanning tunneling microscope as a tool for putting together only three iron atoms on a conductive platinum substrate (see the Figure, left panel). They were also able to use the magnetic tip in order to write information into a storage register of two of such bits (see the Figure, right panel) which keeps the stored information for hours.

By using conductive platinum as a substrate, the researchers were able to achieve an intriguing magnetic structure inside the bit and substrate (see the Figure, left panel): the magnetization of the individual constituents of the bit is not aligned parallel, as in conventional magnetic storage elements, but in a much more complex, so called non-collinear, fashion.

This non-collinearity enables to transmit the stored information to neighboring components using a large variety of angles between the magnetizations, other than just 0° and 180°, which will add more flexibility to information processing schemes.

Figure: Left panel: Illustration of the constructed magnetic bit composed of only three iron atoms on a platinum substrate. The arrows indicate the peculiar magnetization inside the bit which carries the information. Right panel: Magnetic images of the four possible states of a register of two of such magnetic bits. In these images, the height of the two bits reflects their state (0, low and 1, high). The iron atom in the back serves as a marker for the height of a tenth of a nanometer.

Original publication:
A gateway towards non-collinear spin processing using three-atom magnets with strong substrate coupling, J. Hermenau, J. Ibañez-Azpiroz, Chr. Hübner, A. Sonntag, B. Baxevanis, K. T. Ton, M. Steinbrecher, A. A. Khajetoorians, M. dos Santos Dias, S. Blügel, R. Wiesendanger, S. Lounis, and J. Wiebe,
Nature Communications (2017).
DIO: 10.1038/s41467-017-00506-7

Weitere Informationen:

http://www.nanoscience.de
http://www.sfb668.de

Heiko Fuchs | idw - Informationsdienst Wissenschaft

More articles from Information Technology:

nachricht First machine learning method capable of accurate extrapolation
13.07.2018 | Institute of Science and Technology Austria

nachricht A step closer to single-atom data storage
13.07.2018 | Ecole Polytechnique Fédérale de Lausanne

All articles from Information Technology >>>

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 >>>