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 New Material to Push the Boundaries of Silicon-Based Electronics
21.01.2019 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

nachricht Saving energy by taking a close look inside transistors
10.01.2019 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: Ten-year anniversary of the Neumayer Station III

The scientific and political community alike stress the importance of German Antarctic research

Joint Press Release from the BMBF and AWI

The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...

Im Focus: Ultra ultrasound to transform new tech

World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles

The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

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

12.12.2018 | Event News

 
Latest News

Scientists discover new 'architecture' in corn

21.01.2019 | Life Sciences

Broadband achromatic metalens focuses light regardless of polarization

21.01.2019 | Physics and Astronomy

Nuclear actin filaments determine T helper cell function

21.01.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>