Featured Research

from universities, journals, and other organizations

'Spintronics' Could Enable A New Generation Of Electronic Devices, Physicists Say

Date:
August 11, 2003
Source:
Stanford University
Summary:
Moore's Law -- a dictum of the electronics industry that says the number of transistors that fit on a computer chip will double every 18 months -- may soon face some fundamental roadblocks.

Moore's Law - a dictum of the electronics industry that says the number of transistors that fit on a computer chip will double every 18 months - may soon face some fundamental roadblocks. Most researchers think there'll eventually be a limit to how many transistors they can cram on a chip. But even if Moore's Law could continue to spawn ever-tinier chips, small electronic devices are plagued by a big problem: energy loss, or dissipation, as signals pass from one transistor to the next. Line up all the tiny wires that connect the transistors in a Pentium chip, and the total length would stretch almost a mile. A lot of useful energy is lost as heat as electrons travel that distance.

Theoretical physicists at Stanford and the University of Tokyo think they've found a way to solve the dissipation problem by manipulating a neglected property of the electron - its ''spin,'' or orientation, typically described by its quantum state as ''up'' or ''down.'' They report their findings in the Aug. 7 issue of Science Express, an online version of Science magazine. Electronics relies on Ohm's Law, which says application of a voltage to many materials results in the creation of a current. That's because electrons transmit their charge through the materials. But Ohm's Law also describes the inevitable conversion of electric energy into heat when electrons encounter resistance as they pass through materials.

''We have discovered the equivalent of a new 'Ohm's Law' for spintronics - the emerging science of manipulating the spin of electrons for useful purposes,'' says Shoucheng Zhang, a physics professor at Stanford. Professor Naoto Nagaosa of the University of Tokyo and his research assistant, Shuichi Murakami, are Zhang's co-authors. ''Unlike the Ohm's Law for electronics, the new 'Ohm's Law' that we've discovered says that the spin of the electron can be transported without any loss of energy, or dissipation. Furthermore, this effect occurs at room temperature in materials already widely used in the semiconductor industry, such as gallium arsenide. That's important because it could enable a new generation of computing devices.''

Zhang uses a celestial analogy to explain two important properties of electrons - their center of mass and their spin: ''The Earth has two kinds of motion. One is that its center of mass moves around the Sun. But the other is that it also spins by itself, or rotates. The way it moves around the Sun gives us the year, but the way it rotates around by itself gives us the day. The electron has similar properties.'' While electronics uses voltage to move an electron's center of mass, spintronics uses voltage to manipulate its spin.

The authors predict that application of an electric field will cause electrons' spins to flow together collectively in a current. The applied electric force, the spins and the spin current align in three different directions that are all perpendicular to each other (see film of the effect at http://news-service.stanford.edu/news/2003/august20/zhang-video-820.html).

''This is a remarkable thing,'' explains Zhang. ''I push you forward and you move sideways - not in the direction that I'm pushing you.''

So far, only superconductors are known to carry current without any dissipation. However, extremely low temperatures, typically -150 degree Celsius, are required for the dissipationless current to flow inside a superconductor. Unlike electronic superconductors being investigated in advanced laboratories throughout the world, whose operating temperatures are too low to be practical in commercial devices, Zhang, Nagaosa and Murakami theorize that the dissipationless spin current will flow even at room temperature.

''This [the work reported in the paper] is a theoretical prediction,'' Zhang says. ''The next step is to work closely with experimental labs to verify this prediction and to demonstrate this effect.'' That will require creating materials and testing them with a sensitive spin detector. ''Once this is done we can go ahead to propose different device structures which take advantage of this effect,'' he says.

Zhang characterizes his work as fundamental research but says spintronics is already making its way into devices in other labs. With lack of dissipation, spintronics may be the best mechanism for creating ever-smaller devices. The potential market is enormous, he says. ''In maybe a 10-year timeframe, spintronics will be on par with electronics,'' he predicts. ''That's why there's a huge race going on around the world.''

The National Science Foundation and the Department of Energy in the United States and the Ministry of Education, Culture, Sports, Science and Technology in Japan funded the work.


Story Source:

The above story is based on materials provided by Stanford University. Note: Materials may be edited for content and length.


Cite This Page:

Stanford University. "'Spintronics' Could Enable A New Generation Of Electronic Devices, Physicists Say." ScienceDaily. ScienceDaily, 11 August 2003. <www.sciencedaily.com/releases/2003/08/030811070203.htm>.
Stanford University. (2003, August 11). 'Spintronics' Could Enable A New Generation Of Electronic Devices, Physicists Say. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2003/08/030811070203.htm
Stanford University. "'Spintronics' Could Enable A New Generation Of Electronic Devices, Physicists Say." ScienceDaily. www.sciencedaily.com/releases/2003/08/030811070203.htm (accessed September 30, 2014).

Share This



More Computers & Math News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Apple Releases 'Shellshock' Fix Despite Few Affected Users

Apple Releases 'Shellshock' Fix Despite Few Affected Users

Newsy (Sep. 29, 2014) Apple released a security fix for the "Shellshock" vulnerability Monday, though it says only "advanced UNIX users" of OS X need it. Video provided by Newsy
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. Video provided by Newsy
Powered by NewsLook.com
New Facebook Ad Platform Goes Where You Go On The Web

New Facebook Ad Platform Goes Where You Go On The Web

Newsy (Sep. 29, 2014) Called Atlas, the platform allows advertisers to place ads based on Facebook info on sites outside of Facebook. Video provided by Newsy
Powered by NewsLook.com
Google Tightens Requirements For Android Manufacturers

Google Tightens Requirements For Android Manufacturers

Newsy (Sep. 27, 2014) Phonemakers who want to use Google’s software in their devices will have to stick to more stringent requirements. Video provided by Newsy
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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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