Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Driving an Electron Spin Vortex “Skyrmion” with a Microcurrent

Large Advance toward Realization of Technology for Manipulation of Magnetic Information with Low Current Density 1/100,000th that of Conventional Technology
RIKEN, the University of Tokyo, and NIMS succeeded in forming a skyrmion crystal, in which electron spin is aligned in a vortex shape, in a microdevice using the helimagnet FeGe, and driving the skyrmion crystal with an ultra-low current density less than 1/100,000 that of the current necessary to drive magnetic domain walls in ferromagnets.

As a result of this research, it was possible to obtain guidelines for the realization of a technology for manipulating the states of magnetic information media with extremely low power consumption.
This research result was achieved by a team headed by Dr. Xuizhen Yu, a Postdoctoral Researcher in the Strong-Correlation Physics Research Team of the Correlated Electron Research Group of the RIKEN Advanced Science Institute, Group Director Prof. Yoshinori Tokura of the University of Tokyo Graduate School of Engineering, and Dr. Koji Kimoto, Unit Director of the Surface Physics and Structure Unit, Advanced Key Technologies Division of NIMS.

Magnetic memory devices that use the direction of electron spin, which is the source of magnetism, as digital information have attracted attention as devices with the important features of high speed and non-volatility, etc. In recent years, numerous attempts have been made to manipulate that magnetic information electrically without utilizing a magnetic field. If a current is passed through a ferromagnet, it is possible to move the magnetic domain walls, which are the boundaries between domains where magnetization is upward-oriented and domains with downward orientation (at domain walls, the direction of magnetic spin gradually changes). Therefore, reversal of magnetization becomes possible and information can be written. However, in order to drive the domain walls in this manner, a large current density of at least approximately 105 A/cm2 was necessary. Because this causes large energy loss, in other words, large energy consumption, a method of manipulating magnetic information media with a smaller current density had been desired.

The research team investigated various functional magnetic materials, and in 2010, succeeded in forming and observing a skyrmion crystal by applying a weak magnetic field of less than 200 millitesla (mT) to a thin slice of the helimagnet FeGe at near room temperature. In the present research, the team fabricated microdevices with a length of 165ìm, width of 100ìm, and thicknesses of 100nm to 30ìm using the same FeGe. When a magnetic field of approximately 150mT at temperatures from -23°C to near-room temperature (-3°C) was applied, skymrion crystals in which a stable skyrmion with a diameter of about 70nm was aligned in a triangular lattice shape were observed. The team succeeded in driving the skymrion crystal with an ultra-low current density (the minimum density is approximately 5A/cm2), which is less than 1/100,000th that required to drive magnetic domain walls in conventional ferromagnets. The fact that the skymrion can be driven with this extremely low current density represents the first step toward the development of low power consumption magnetic memory devices using skymrions as an information medium. Various applications can also be expected in the field of spintronics, which is currently an area of active research as a next-generation electronic technology.

The main portion of the research result was achieved in the “Quantum Science on Strong Correlation” project (Core Researcher: Yoshinori Tokura) of the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST) of the Japan Society for the Promotion of Science (JSPS), with system design by the Council for Science and Technology Policy, and was supported by the JSPS. Part of the research was also supported by the Strategic Basic Research Programs/ERATO (Exploratory Research for Advanced Technology) Type Research Projects of the Japan Science and Technology Agency (JST) and the Nanotechnology Network of Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT), and has been published in the online edition of the British science journal “Nature Communications” on August 7 (August 8 Japan time).

For more detail

Dr. Xiuzhen Yu
Strong-Correlation Physics Research Team,
Correlated Electron Research Group,
Advanced Science Institute, RIKEN
TEL: +81-48-462-1111(ext. 6324)
FAX: +81-48-462-4703

Prof. Yoshinori Tokura
Team Leader, Strong-Correlation Physics Research Team,
Group Director, Correlated Electron Research Group,
Advanced Science Institute, RIKEN

For more detail about “Quantum Science on Strong Correlation” project

Dr. Izumi Hirabayashi
Deputy Group Director, Correlated Electron Research Group, Advanced Science Institute,

Team Leader, Strong-Correlation Research Support Team, Correlated Electron Research Group, Advanced Science Institute, RIKEN
TEL: +81-48-462-4660
FAX: +81-48-462-1687

For general inquiry
RIKEN Public Relations Office

Mikiko Tanifuji | Research asia research news
Further information:

More articles from Materials Sciences:

nachricht How nanoscience will improve our health and lives in the coming years
27.10.2016 | University of California - Los Angeles

nachricht 3-D-printed structures shrink when heated
26.10.2016 | Massachusetts Institute of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Prototype device for measuring graphene-based electromagnetic radiation created

28.10.2016 | Power and Electrical Engineering

Gamma ray camera offers new view on ultra-high energy electrons in plasma

28.10.2016 | Physics and Astronomy

When fat cells change their colour

28.10.2016 | Life Sciences

More VideoLinks >>>