Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Construction set of magnon logic extended: Magnon spin currents controlled via spin valve structure

15.03.2018

Magnon spintronics employs magnons instead of electrical charges for information processing

In the emerging field of magnon spintronics, researchers investigate the possibility to transport and process information by means of so-called magnon spin currents. In contrast to electrical currents, on which todays information technology is based, magnon spin currents do not conduct electrical charges but magnetic momenta.


Depending on the magnetic configuration of the spin valve, the electrical signal is transmitted (bottom) or suppressed (top).

ill./©: Joel Cramer

These are mediated by magnetic waves, or so-called magnons, which analogous to sound waves propagate through magnetic materials. One fundamental building block of magnon spintronics is magnon logic, which, for instance, allows to perform logic operations and thus information processing by the superposition of spin currents. An international team of physicists from Johannes Gutenberg University Mainz (JGU) and the University of Konstanz in Germany and Tohoku University in Sendai, Japan, recently succeeded in adding a further element to the construction set of magnon logic.

In a so-called spin valve structure, which amongst others comprises several ferromagnets, it was possible to demonstrate that the detection efficiency of magnon currents depends on the magnetic configuration of the device. Generally, this allows to control the transmission or blocking of incoming information. The research work has been published in the online journal Nature Communications with a fellow of the JGU-based Graduate School of Excellence Materials Science in Mainz (MAINZ) as first author.

The essential aim of magnon spintronics is to replace the electrical charge as information carrier in information technological concepts by magnons. Among other things, magnons offer the possibility of wave-based computing, which provides more options for logical data processing. Magnons furthermore propagate in magnetic insulators with comparably small losses, which holds out the prospect of the implementation of improved energy efficiency of data processing.

The investigated spin valve structure is a trilayer system comprising the insulating ferromagnet yttrium iron garnet (YIG), the insulating antiferromagnet cobalt(II) oxide (CoO), and the metallic ferromagnet cobalt (Co): YIG/CoO/Co. By means of the oscillating magnetic fields of irradiated microwaves the deliberate rotation of the YIG magnetization is induced, which emits a magnon spin current into the CoO. In the metallic Co layer the magnon spin current gets converted into a charge current due to the so-called inverse spin Hall effect and is thus detected.

Switch-like device forwards or suppresses magnon current as electric signal

The experiment demonstrated that the amplitude of the detected signal strongly depends on the magnetic configuration of the spin valve. In the case of antiparallel alignment of the YIG and Co magnetization, the signal amplitude is approximately 120 percent larger than in the parallel state. The repetitive switching of the Co magnetization further revealed the robustness of the effect and likewise its suitability for long-time operation.

"Altogether, this effect to some extent allows the implementation of a switch-like device, which suppresses or forwards the magnon current as an electrical signal," said Joel Cramer, first author of the article and member of the Graduate School of Excellence Materials Science in Mainz. "The result of our experiment is an effect which might find application in prospective magnon logic operations, thus yielding an essential contribution to the field of magnon spintronic", Cramer added.

Collaboration of internationally leading research teams in the field of spintronics

"Our collaboration with internationally leading groups within the field of spin transport in insulators follows a long tradition, especially in the Collaborative Research Center Spin-X, funded by the German Research Foundation (DFG). With the support of the German Academic Exchange Service (DAAD) and the MAINZ Graduate School, this collaboration could even be extended to long-term stays of guest students from Japan here in Mainz and vice versa," said Professor Mathias Kläui, Director of MAINZ.

"The work now published in Nature Communications was mainly performed during a guest stay of two of our students and myself in Japan. I enjoyed it very much to be closer to the experiment and to even contribute to the measurements. Hence, I would like to thank the group of Professor Saitoh and the Institute for Materials Research at Tohoku University for their hospitality and the excellent collaboration," added Kläui.

The theory for this work was jointly developed by the groups in Mainz and Konstanz. There is a particularly strong, long, and fruitful collaboration with the Magnetic Materials group of Professor Ulrich Nowak at the University of Konstanz. "Now that our third joint project proposal was evaluated positively, I am looking forward to further intense collective work," added Kläui.

The MAINZ Graduate School of Excellence was approved through the German Federal and State Excellence Initiative in 2007 and received a five-year funding extension in the second round in 2012. It consists of work groups from Johannes Gutenberg University Mainz, TU Kaiserslautern, and the Max Planck Institute for Polymer Research in Mainz and offers excellent national and international doctoral candidates in natural science disciplines an exceptional training in materials science. One of its focal research areas is spintronics, where cooperation with leading international partners plays an important role.

Problems of spin transport and the creation and detection of spin currents are investigated within MAINZ as part of the CRC/Transregio 173: Spin+X, which has been funded by the German Research Foundation since 2016.

Image:
http://www.uni-mainz.de/bilder_presse/08_physik_komet_magnonen_ventil.jpg
Depending on the magnetic configuration of the spin valve, the electrical signal is transmitted (bottom) or suppressed (top).
ill./©: Joel Cramer

Publication:
Joel Cramer et al.
Magnon detection using a ferroic collinear multilayer spin valve
Nature Communications, 14 March 2018
DOI: 10.1038/s41467-018-03485-5
https://www.nature.com/articles/s41467-018-03485-5

Contact:
Joel Cramer
Physics of Condensed Matter
Institute of Physics
Johannes Gutenberg University Mainz
55099 Mainz, GERMANY
phone +49 6131 39-23637
fax +49 6131 39-24076
e-mail: jocramer@uni-mainz.de

Professor Dr. Mathias Kläui
Physics of Condensed Matter
Institute of Physics
Johannes Gutenberg University Mainz
55099 Mainz, GERMANY
phone +49 6131 39-23633
e-mail: klaeui@uni-mainz.de
https://www.klaeui-lab.physik.uni-mainz.de/homepage-prof-dr-mathias-klaeui/

Related links:
https://www.klaeui-lab.physik.uni-mainz.de/ – Kläui Laboratory at the Institute of Physics at JGU ;
https://www.iph.uni-mainz.de/index_ENG.php – Institute of Physics at JGU
http://www.mainz.uni-mainz.de/ - Graduate School of Excellence Materials Science in Mainz

Read more:
http://www.uni-mainz.de/presse/20410_ENG_HTML.php – press release "International team of scientists unveils fundamental properties of the spin Seebeck effect” (28 July 2016)

Petra Giegerich | idw - Informationsdienst Wissenschaft

More articles from Physics and Astronomy:

nachricht CCNY-Yale researchers make shape shifting cell breakthrough
12.12.2018 | City College of New York

nachricht Electronic evidence of non-Fermi liquid behaviors in an iron-based superconductor
11.12.2018 | Science China Press

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: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

New discoveries predict ability to forecast dementia from single molecule

12.12.2018 | Health and Medicine

CCNY-Yale researchers make shape shifting cell breakthrough

12.12.2018 | Physics and Astronomy

Pain: Perception and motor impulses arise in the brain independently of one another

12.12.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>