12 September 2018

Nature publication

Physicists progress towards cooler and faster computing using rust

Schematische weergave van een magnon of spingolf

The main component of rust is a cheap and promising material for ICT applications with low excess heating at increased speeds. This has been demonstrated by experimental and theoretical physicists of the Johannes Gutenberg University Mainz, the Norwegian University of Science and Technology, and Rembert Duine and Scott Bender from Utrecht University. Their results are published in the scientific journal Nature on 13 September.

At the moment, bits and bytes are transported and processed by means of electronical devices, such as transistors and on-chip wires. In the process, they also produce quite a lot of heat. Moreover, the speed of the information they are capable of transporting is limited. These properties are slowing down the pace of progress in the field of information technology, that needs smaller and faster devices. This Nature publication shows that a group of magnetic materials, known as antiferromagnets, present a cheap and promising alternative to information transport at higher speeds, and with less excess heating. Another advantage is that use of these materials can save precious energy.

Magnetic wave

Ferromagnetic materials, such as iron, are composed of magnetic domains that are oriented in the same direction and hence react in the same way to a magnetic field. In antiferromagnetic materials, such as rust (iron oxide), the domains are arranged in patterns that produce a magnetic field in opposite directions and cancel out each other. However, it is possible to create a magnetic wave in these materials, called a magnon. These magnons created in antiferromagnet materials can be used in ICT-applications to carry the bits and bytes.

Schematische weergave van het experiment
An electrical current in a platinum wire (l.) creates a magnetic wave in the antiferromagnetic iron oxide (red and blue waves) to be measured as a voltage in a second platinum wire (r.). The arrows represent the antiferromagnetic order of the iron oxide.

Faster and smaller

Antiferromagnet-based devices can potentially be operated thousands of times faster than current technologies. Magnons also potentially do not have the disadvantage of producing excess heat. This makes it possible to produce increasingly smaller components with an increased information density.

Large distances

In their study, the researchers used platinum wires on top of the insulating iron oxide to allow an electric current to pass close by. This electric current leads to a transfer of energy from the platinum into the iron oxide, creating magnons. The iron oxide was found to carry information as far as the large distances needed for computing devices.

Ten to fifteen years

Rembert Duine
Rembert Duine

“This result demonstrates the suitability of antiferromagnets to replace currently used components. Fast antiferromagnet insulator-based devices are now conceivable”, says Dr. Romain Lebrun of Johannes Gutenberg University.” According to Rembert Duine from Utrecht University and Eindhoven University of Technology, who participated in the theoretical study of the system, this technique could be implemented in real-world applications within ten to fifteen years.

Publication

‘Electrically tunable long-distance transport in crystalline antiferromagnetic iron oxide’
R. Lebrun, A. Ross, S. A. Bender*, A. Qaiumzadeh, L. Baldrati, J. Cramer, A. Brataas, R. A. Duine*, & M. Kläui
Nature, 13 September 2018,

*Affiliated with Utrecht University; Rembert Duine is also part-time Professor of Spin-based Nanoelectronics at Eindhoven University of Technology, the Netherlands.

Read more

  • The principle of this study is the same as described in a paper in Nature Physics in 2015 by Rembert Duine and colleagues, but then with ferromagnetic materials. Also read the press release.
  • Last year, Scott Bender and Rembert Duine together with the colleagues from the Norwegian University of Science and Technology published a paper on Spin Transport Through Antiferromagnets in Physical Review Letters.

This research was funded in part by the European Research Council and the Netherlands Organisation for Scientific Research (NWO).