Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Energy-efficient spin current can be controlled by magnetic field and temperature

17.08.2018

SCMR effect simplifies the design of fundamental spintronic components

The transition from light bulbs to LEDs has drastically cut the amount of electricity we use for lighting. Most of the electricity consumed by incandescent bulbs was, after all, dissipated as heat. We may now be on the verge of a comparable breakthrough in electronic computer components.


Up to now, these have been run on electricity, generating unwanted heat. If spin current were employed instead, computers and similar devices could be operated in a much more energy-efficient manner. Dr. Olena Gomonay from Johannes Gutenberg University Mainz (JGU) in Germany and her team together with Professor Eiji Saitoh from the Advanced Institute for Materials Research (AIMR) at Tohoku University in Japan and his work group have now discovered an effect that could make such a transition to spin current a reality. This effect significantly simplifies the design of fundamental spintronic components.

Touching a computer that has been running for some time, you will feel heat. This heat is an – undesirable – side effect of the electric current. Undesirable because the heat generated, naturally, also consumes energy. We are all familiar with this effect from light bulbs, which became so hot after being on for hours that they could burn your fingers.

This is because light bulbs converted only a fraction of the energy required to do their job of creating light. The energy used by LEDs, on the other hand, is almost completely used for lighting, which is why they don’t become hot. This makes LEDs significantly more energy-efficient than traditional incandescent bulbs.

Instead of using an electric current composed of charged particles, a computer using a stream of particles with a spin other than zero could manipulate the material of its components in the same way to perform calculations. The primary difference is that no heat is generated, the processes are much more energy-efficient.

Dr. Olena Gomonay from Mainz University and Professor Eiji Saitoh from Tohoku University have now laid the foundations for using these spin currents. More precisely, they have used the concept of spin currents and applied it to a specific material. Gomonay compares the spin currents involved with how our brains work: "Our brains process immeasurable amounts of information, but they don't heat up in the process. Nature is, therefore, way ahead of us." The team from Mainz is hoping to emulate this model.

Drastic change in current flow

How well spin currents flow depends on the material – just like in the case of electric current. While spin currents can always flow in ferromagnetic materials, in antiferromagnetic materials states with low resistance alternate with those with high resistance. "We have now found a way to control spin currents by means of a magnetic field and temperature, in other words, to control the resistance of an antiferromagnetic system based on spin," explained Gomonay, summarizing her results.

At a temperature close to the phase transition temperature, Gomonay and her team applied a small magnetic field to the material. While the applied magnetic field alters the orientation of the spin currents to allow them to be easily transported through the material, the temperature has precisely two effects. On the one hand, a higher temperature causes more particles of the material to be in excited states, meaning there are more spin carriers that can be transported, which makes spin transport easier. On the other hand, the high temperature makes it possible to operate at a low magnetic field.

Thus the resistance and the current flow change drastically by several orders of magnitude. "This effect, which we call spin colossal magnetoresistance or SCMR for short, has the potential to simplify the design of fundamental spintronic components significantly," explained the scientist from Mainz. This is particularly interesting for storage devices such as hard disks. This effect might be employed, for example, to create spin current switches as well as spin current based storage media.

Wissenschaftliche Ansprechpartner:

Dr. Olena Gomonay
INSPIRE – Interdisciplinary Spintronics Research
Institute of Physics
Johannes Gutenberg University Mainz
55099 Mainz, GERMANY
phone +49 6131 39-23643
e-mail: ogomonay@uni-mainz.de
https://www.sinova-group.physik.uni-mainz.de/team/olena-gomonay/

Elena Hilp
INSPIRE – Interdisciplinary Spintronics Research
Institute of Physics
Johannes Gutenberg University Mainz
55099 Mainz, GERMANY
phone +49 6131 39-21259
e-mail: spice@uni-mainz.de
https://www.sinova-group.physik.uni-mainz.de/

Originalpublikation:

Z. Qiu et al., Spin colossal magnetoresistance in an antiferromagnetic insulator, Nature Materials 17, 577-580, 28 May 2018,
DOI:10.1038/s41563-018-0087-4
https://www.nature.com/articles/s41563-018-0087-4

Weitere Informationen:

https://www.sinova-group.physik.uni-mainz.de/ – Interdisciplinary Spintronics Research group (INSPIRE) at JGU ;
https://www.spice.uni-mainz.de/ – Spin Phenomena Interdisciplinary Center (SPICE) at JGU ;
https://www.blogs.uni-mainz.de/fb08-iph-eng/ – JGU Institute of Physics

Petra Giegerich | idw - Informationsdienst Wissenschaft

More articles from Power and Electrical Engineering:

nachricht Patented nanostructure for solar cells: Rough optics, smooth surface
18.09.2018 | Helmholtz-Zentrum Berlin für Materialien und Energie GmbH

nachricht With Gallium Nitride for a Powerful 5G Cellular Network - EU project “5G GaN2” started
17.09.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

Im Focus: Graphene enables clock rates in the terahertz range

Graphene is considered a promising candidate for the nanoelectronics of the future. In theory, it should allow clock rates up to a thousand times faster than today’s silicon-based electronics. Scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) and the University of Duisburg-Essen (UDE), in cooperation with the Max Planck Institute for Polymer Research (MPI-P), have now shown for the first time that graphene can actually convert electronic signals with frequencies in the gigahertz range – which correspond to today’s clock rates – extremely efficiently into signals with several times higher frequency. The researchers present their results in the scientific journal “Nature”.

Graphene – an ultrathin material consisting of a single layer of interlinked carbon atoms – is considered a promising candidate for the nanoelectronics of the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

 
Latest News

World's first passive anti-frosting surface fights ice with ice

18.09.2018 | Materials Sciences

A novel approach of improving battery performance

18.09.2018 | Materials Sciences

Scientists use artificial neural networks to predict new stable materials

18.09.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>