Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Spin currents heat up: Long-range spin currents induced by heat herald a new era for spintronic applications

Figure 1: Schematic of the experimental setup for the spin Seebeck effect. A magnetic metal such as Ni81Fe19 is exposed to two different temperatures at its ends. With the magnetic magnetization (red arrow) in the plane of the device, a spin voltage results, so that spins of different orientation are at either ends of the sample. The spin voltage is measured through thin platinum (Pt) strips where the spin Hall effect (SHE) converts spin voltages into electric voltages.
Figure 1: Schematic of the experimental setup for the spin Seebeck effect. A magnetic metal such as Ni81Fe19 is exposed to two different temperatures at its ends. With the magnetic magnetization (red arrow) in the plane of the device, a spin voltage results, so that spins of different orientation are at either ends of the sample. The spin voltage is measured through thin platinum (Pt) strips where the spin Hall effect (SHE) converts spin voltages into electric voltages.

Abstract:
Modern electronics is based on the transport of electrons, generated by a difference in electric voltage. In a bid for faster and smaller electronic devices, researchers have turned to the spin of electrons, or spintronics. However, sustaining spin currents has proven difficult. Now researchers from the RIKEN Advanced Science Institute in Wako with scientists from Keio University, Yokohoma, and Tohoku University, Sendai, have—for the first time—observed the so-called spin Seebeck effect, which is able to generate pure spin currents across macroscopic distances.

Spin currents heat up: Long-range spin currents induced by heat herald a new era for spintronic applications

Japan | Posted on February 5th, 2009

The classic Seebeck effect describes the generation of an electric voltage when the ends of a material are at different temperatures. As such, it is used in thermoelectric devices that convert heat into electricity.

In a similar fashion, as reported by the researchers in Nature1, the spin Seebeck effect reported uses a temperature gradient in a magnetic material to create a flow of electron spins in the absence of any external voltage. As a result, spins of opposite polarization assemble at the two ends of the sample, creating a ‘spin voltage' caused by the different spin polarizations at both ends. This use of thermal effects in spintronics is novel and unexpected. "The electron spin is usually controlled by magnetic fields, so nobody has thought about a thermoelectric response," says Wataru Koshibae from the research team.

The discovery of the spin Seebeck effect is enabled by the so-called spin Hall effect. Through interactions between the spin current and the atoms in a metal, electrons of different spin orientations get scattered to opposite ends of the metal, creating an electrical voltage. The spin voltage created by the spin Seebeck effect is then detected by thin platinum sheets placed at both ends of the sample (Fig. 1).

Importantly, in this setup the electrons don't move at all, and only spins travel along the sample. This is markedly different to most other schemes where undesirable parallel electronic currents are unavoidable. In addition, there appears to be no limit to the distances along which spin currents can be sustained. "The spin Seebeck effect occurs in samples almost 1 cm long, much longer than the usual spin current decay lengths of 1 nm," comments Koshibae.

This first observation of the spin Seebeck effect therefore marks a new era in spintronics and opens the door to novel applications. Long-distance spin current are critical to the realization of spintronic devices, and these results offer the generation of spin currents simply through temperature effects.
Reference

1. Uchida, K., Takahashi, S., Harii, K., Ieda, J., Koshibae, W., Ando, K. Maekawa, S. & Saitoh, E. Observation of the spin Seebeck effect. Nature 455, 778-781 (2008).

The corresponding author for this highlight is based at the RIKEN Theoretical Design 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

Tissue regeneration using anti-inflammatory nanomolecules August 22nd, 2014

A breakthrough in imaging gold nanoparticles to atomic resolution by electron microscopy August 22nd, 2014

Ultra-short pulse lasers & Positioning August 21st, 2014

Malvern’s Dr Alan Rawle talks TLAs in plenary lecture at Particulate Systems Analysis conference August 21st, 2014

Spintronics

Molecular engineers record an electron's quantum behavior August 14th, 2014

Diamond defect interior design: Planting imperfections called 'NV centers' at specific spots within a diamond lattice could advance quantum computing and atomic-scale measurement August 5th, 2014

University of Illinois study advances limits for ultrafast nano-devices July 10th, 2014

Harnessing magnetic vortices for making nanoscale antennas: Scientists explore ways to synchronize spins for more powerful nanoscale electronic devices April 30th, 2014

Discoveries

Tissue regeneration using anti-inflammatory nanomolecules August 22nd, 2014

A breakthrough in imaging gold nanoparticles to atomic resolution by electron microscopy August 22nd, 2014

Shaping the Future of Nanocrystals: Berkeley Lab Researchers Obtain First Direct Observation of Facet Formation in Nanocubes August 21st, 2014

Water window imaging opportunity: A new theoretical study elucidates mechanisms that could help in producing coherent radiations, ultimately promoting high-contrast imaging of biological samples August 21st, 2014

Announcements

Tissue regeneration using anti-inflammatory nanomolecules August 22nd, 2014

A breakthrough in imaging gold nanoparticles to atomic resolution by electron microscopy August 22nd, 2014

Malvern’s Dr Alan Rawle talks TLAs in plenary lecture at Particulate Systems Analysis conference August 21st, 2014

Water window imaging opportunity: A new theoretical study elucidates mechanisms that could help in producing coherent radiations, ultimately promoting high-contrast imaging of biological samples August 21st, 2014

Quantum nanoscience

Rice physicist emerges as leader in quantum materials research: Nevidomskyy wins both NSF CAREER Award and Cottrell Scholar Award August 20th, 2014

Molecular engineers record an electron's quantum behavior August 14th, 2014

Moore quantum materials: Recipe for serendipity - Moore Foundation grant will allow Rice physicist to explore quantum materials August 12th, 2014

Measuring the Smallest Magnets July 28th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE