Featured Research

from universities, journals, and other organizations

A 'spin ratchet' paves the way for spin computers: New electronic structure for generating spin current

Date:
December 20, 2010
Source:
Institut Català de Nanotecnologia
Summary:
Scientists have proposed and experimentally demonstrated a ratchet concept to control the spin motion. In analogy to a ratchet wrench, which provides uniform rotation from oscillatory motion, such ratchets achieve directed spin transport in one direction, in the presence of an oscillating signal. Most important, this signal could be an oscillatory current that results from environmental charge noise; thus future devices based on this concept could function by gathering energy from the environment.

Scientists have proposed and experimentally demonstrated a ratchet concept to control the spin motion. In analogy to a ratchet wrench, which provides uniform rotation from oscillatory motion, such ratchets achieve directed spin transport in one direction, in the presence of an oscillating signal. Most important, this signal could be an oscillatory current that results from environmental charge noise; thus future devices based on this concept could function by gathering energy from the environment.

The research team from the Institut Català de Nanotecnologia (ICN), in Barcelona, has demonstrated a device that induces electron spin motion without net electric currents, a key step in developing the spin computers of the future.

The results are published in the Dec 17 issue of the journal Science. The authors are Marius V. Costache and Sergio O. Valenzuela, an ICREA Professor who is leader of the Physics and Engineering of Nanodevices Group at ICN.

Spintronics is a branch of electronics that aims to use the electron spin rather than its charge to transport and store information. The electron spin comes in two forms, "spin up" or "spin down," and would allow significantly more data to be stored and analyzed than is possible with current electronics. Moreover, spin computers would be able to process vast amounts of information while using less energy and generating much less heat than conventional computers.

Advances in spintronics have already impacted commercial products, enabling a huge increase in storage capacity of magnetic hard disks. However, the devices comprise ferromagnetic multilayers that act as spin filters and require conventional electrical charge currents in order to work. To garner the full potential of spintronics, further fundamental advances are urgently needed.

Researchers working in this field face a key challenge: how to generate and control spins without the simultaneous generation of electric current, and the resultant energy losses? This would enable not just data storage, but calculations to be realized directly using spin states.

As reported in the journal Science, Prof. Valenzuela and Dr. Costache have proposed and experimentally demonstrated a ratchet concept to control the spin motion. In analogy to a ratchet wrench, which provides uniform rotation from oscillatory motion, such ratchets achieve directed spin transport in one direction, in the presence of an oscillating signal. Most important, this signal could be an oscillatory current that results from environmental charge noise; thus future devices based on this concept could function by gathering energy from the environment.

The efficiency of the ratchet can be very high. Reported results show electron polarizations of the order of 50%, but they could easily exceed 90% with device design improvements. The spin ratchet, which relies on a single electron transistor with a superconducting island and normal metal leads, is able to discriminate the electron spin, one electron at a time. The devices can also function in a "diode" regime that resolves spin with nearly 100% efficacy and, given that they work at the single-electron level, they could be utilized to address fundamental questions of quantum mechanics in the solid state or to help prepare the path for ultrapowerful quantum or spin computers.

The main drawback of the devices is that they work at low temperature. However, this does not represent a problem for quantum computing applications as solid state implementations of quantum computers will most likely require similar working conditions. Future research at the ICN will focus on increasing the spin ratchet efficiency and testing different ratchet protocols to implement a working device at room temperature.


Story Source:

The above story is based on materials provided by Institut Català de Nanotecnologia. Note: Materials may be edited for content and length.


Journal Reference:

  1. Marius V. Costache and Sergio O. Valenzuela. Experimental Spin Ratchet. Science, 17 December 2010: Vol. 330 no. 6011 pp. 1645-1648 DOI: 10.1126/science.1196228

Cite This Page:

Institut Català de Nanotecnologia. "A 'spin ratchet' paves the way for spin computers: New electronic structure for generating spin current." ScienceDaily. ScienceDaily, 20 December 2010. <www.sciencedaily.com/releases/2010/12/101216142525.htm>.
Institut Català de Nanotecnologia. (2010, December 20). A 'spin ratchet' paves the way for spin computers: New electronic structure for generating spin current. ScienceDaily. Retrieved April 25, 2014 from www.sciencedaily.com/releases/2010/12/101216142525.htm
Institut Català de Nanotecnologia. "A 'spin ratchet' paves the way for spin computers: New electronic structure for generating spin current." ScienceDaily. www.sciencedaily.com/releases/2010/12/101216142525.htm (accessed April 25, 2014).

Share This



More Computers & Math News

Friday, April 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Will New FCC Rules Trigger Death Of Net Neutrality?

Will New FCC Rules Trigger Death Of Net Neutrality?

Newsy (Apr. 24, 2014) — The Federal Communications Commission will reportedly propose new rules for Net neutrality that could undermine the principles of a free and open Web. Video provided by Newsy
Powered by NewsLook.com
Apple Beats Estimates, Most Looking to Second Half of 2014

Apple Beats Estimates, Most Looking to Second Half of 2014

TheStreet (Apr. 24, 2014) — TheStreet's Stephanie Link and Real Money Contributor Dan Nathan discuss Apple's first quarter results. Link and Nathan expected the tech giant to lower guidance for the current quarter which they felt could send shares lower and present a buying opportunity. Nathan says options are cheap because Apple has been aggressively buying back shares. Video provided by TheStreet
Powered by NewsLook.com
Raw: Obama Plays Soccer With Japanese Robot

Raw: Obama Plays Soccer With Japanese Robot

AP (Apr. 24, 2014) — President Obama briefly played soccer with a robot during his visit to Japan on Thursday. The President has been emphasizing technology along with security concerns during his visit. (April 24) Video provided by AP
Powered by NewsLook.com
US Proposes Pay-for-Priority Internet Standards

US Proposes Pay-for-Priority Internet Standards

AP (Apr. 24, 2014) — The Federal Communications Commission is set to propose new rules that would allow Internet service providers to charge content companies for faster delivery of their services over the so-called "last mile" connection to people's homes. (April 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins