Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Spin currents: pure and clean: Switching the orientation of magnetization in a thin metallic film can be achieved using the diffusion of electron spin

Figure 1: Top view of the device used to switch magnetization using a pure spin current. A current, I, is injected from the gold wire into the permalloy film with magnetization M1. The copper wire creates a spin accumulation at the junction (green). The spin diffuses towards the second junction and can switch the magnetization M2 of the second permalloy film. 

Reproduced from Ref. 1 © 2008 Macmillan Publishers Limited
Figure 1: Top view of the device used to switch magnetization using a pure spin current. A current, I, is injected from the gold wire into the permalloy film with magnetization M1. The copper wire creates a spin accumulation at the junction (green). The spin diffuses towards the second junction and can switch the magnetization M2 of the second permalloy film.
Reproduced from Ref. 1 © 2008 Macmillan Publishers Limited

Abstract:
A team of scientists in Japan has demonstrated the possibility of switching the magnetization of a thin magnetic film with a non-conventional and innovative method, achieving a considerable step forward in magnetic data storage and the field known as spintronics.

Spin currents: pure and clean: Switching the orientation of magnetization in a thin metallic film can be achieved using the diffusion of electron spin

Japan | Posted on February 12th, 2009

In magnetic memory devices, information is stored in magnetic elements and typically retrieved by applying a small, external magnetic field. More convenient, however, is the use of a spin-polarized current, in which moving electrons exert a torque on a magnetic element and can switch the direction of its magnetization.

Unfortunately, moving electrons can give rise to electrical noise, which reduces the efficiency of the magnetization control. Now, Yoshichika Otani from the RIKEN Advanced Science Institute in Wako and colleagues have overcome this problem by using a pure spin current1, that is, a diffusion of electron spins without charge motion.

A spin current can be created by the process known as non-local injection: a current is injected into a junction between a metal and a magnetic layer (Fig. 1). When the magnetic element is magnetized, such as a metallic film, electron spins accumulate at the junction, and then diffuse away from the junction to re-equilibrate the spin population in the film. The trick is to then use this spin current to influence the magnetization of another magnetic element placed far from the accumulation point.

Previous attempts to create a pure spin current in this way have all met with limited success. Otani and co-workers therefore focused on optimizing the quality of the interface. In particular, they grew all the layers of their devices in sequence in a single high-vacuum chamber. This prevented possible contamination that could occur while moving a structure between growing chambers.

By examining the electronic transport properties of their device, the researchers were able to demonstrate that when the current injected into the first junction is high enough, it creates a spin current high enough to reverse the magnetization at the second junction. Most importantly, the magnetization can be reversed back by applying the same amount of current in the opposite direction.

Magnetization control using a pure spin current in this way in the high-quality devices fabricated by the team could lead to the realization of very advanced electronic devices. The team believes, for example, that it will be possible to achieve different types of transistors—which have no analogues in current electronics—based only on electron spin.
Reference

1. Yang, T., Kimura, T. & Otani, Y. Giant spin-accumulation signal and pure spin-current-induced reversible magnetization switching. Nature Physics 4, 851-854 (2008).

The corresponding author for this highlight is based at the RIKEN Quantum Nano-Scale Magnetics Team

####

For more information, please click here

Copyright © Riken

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

article

Related News Press

News and information

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

Forces of nature: Interview with microscopy innovators Gerd Binnig and Christoph Gerber August 26th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

Spintronics

Swapping substrates improves edges of graphene nanoribbons: Using inert boron nitride instead of silica creates precise zigzag edges in monolayer graphene August 2nd, 2016

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

A mini-antenna for the data processing of tomorrow: Nature Nanotechnology: Short-wavelength spin waves generated directly for the first time July 20th, 2016

A new spin on reality July 15th, 2016

Chip Technology

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Analog DNA circuit does math in a test tube: DNA computers could one day be programmed to diagnose and treat disease August 25th, 2016

Silicon nanoparticles trained to juggle light: Research findings prove the capabilities of silicon nanoparticles for flexible data processing in optical communication systems August 25th, 2016

Memory Technology

Magnetic atoms arranged in neat rows: FAU physicists enable one-dimensional atom chains to grow August 5th, 2016

New metamaterials can change properties with a flick of a light-switch: Material can lead to new optical devices August 3rd, 2016

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

Research team led by NUS scientists develop plastic flexible magnetic memory device: Novel technique to implant high-performance magnetic memory chip on a flexible plastic surface without compromising performance July 21st, 2016

Discoveries

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

Nanofur for oil spill cleanup: Materials researchers learn from aquatic ferns: Hairy plant leaves are highly oil-absorbing / publication in bioinspiration & biomimetics / video on absorption capacity August 25th, 2016

Unraveling the crystal structure of a -70° Celsius superconductor, a world first: Significant advancement in the realization of room-temperature superconductors August 25th, 2016

Announcements

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

Forces of nature: Interview with microscopy innovators Gerd Binnig and Christoph Gerber August 26th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Graphene under pressure August 26th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic