Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > A new spin on silicon

Abstract:
Chip makers could get the benefits of spintronics without having to abandon silicon

A new spin on silicon

August 02, 2005

For about 40 years, the semiconductor industry has been able to continually shrink the electronic components on silicon chips, packing ever more performance into computers. Now, fundamental physical limits to current technology have the industry scouring the research world for an alternative. In a paper published in the Aug. 1 online edition of Physical Review Letters (PRL), Stanford University physicists present "orbitronics," an alternative to conventional electronics that could someday allow engineers to skirt a daunting limit while still using cheap, familiar silicon.

"The miniaturization of the present-day chips is limited by power dissipation," says Shoucheng Zhang, a professor of physics, applied physics and, by courtesy, electrical engineering, who co-authored the PRL study. "Up to 40 percent of the power in circuits is being lost in heat leakage," which he says will eventually make miniaturization a forbidding task.

Spintronics

In recent years, the search for an alternative to conventional semiconductors has resulted in the discovery of a nanotechnology called "spintronics," which uses a property of electrons called "spin" to produce a novel kind of current that integrated circuits can process as information. Spin refers to how an electron rotates on its axis, similar to the rotation of the Earth. In 2003, Zhang and colleagues at the University of Tokyo showed that producing and manipulating a current of aligned electron spins with an electric field would not involve any losses to heat—a technique they called spintronics.

Zhang now co-directs the IBM-Stanford Spintronic Science and Applications Center, along with Stanford electrical engineering Professor James Harris and IBM research fellow Stuart Parkin. The center, established in 2004, is investigating many applications of spintronics, including room-temperature superconductors and quantum computers.

Playing the angles

For all its potential, a drawback of spintronics is that it doesn't work very well with lighter atoms, such as silicon, which the microelectronics industry prefers. Enter Zhang's new research. In the PRL paper, he and graduate students B. Andrei Bernevig and Taylor L. Hughes show how, in theory, silicon could be used in a related technology they dubbed orbitronics. By using orbitronics, Zhang says, computer chip makers could get the benefits of spintronics without having to abandon silicon.

Both orbitronics and spintronics involve a physical quantity called "angular momentum," a property of any mass that moves around a fixed position, be it a tetherball or an electron.

Like an electric current, which is the flow of negatively charged electrons in a conventional integrated circuit, an orbital current would consist of a flow of electrons with their angular momenta aligned in an orbitronic circuit. "If you push electrons forward with an electric field, then an orbital current will be generated perpendicular to this electric current," Zhang says. "It will not carry charge, but will carry orbital angular momentum perpendicular to the direction in which the electrons are moving."

Therefore, he explains, with orbitronics, silicon would still be able to provide a useful current with no losses to heat at room temperature. Some alternative technologies require cold temperatures that are difficult and expensive to maintain, he adds.

From theory to application

The authors point out that orbitronics still has a long way to go to become an applied technology in the semiconductor industry. "This is so new," Zhang acknowledges. "When something is first discovered it is hard to say. There are many difficulties in the practical world."

Harris agrees, noting that spintronics will likely still take decades to become a mature commercial technology. "It's not going to happen immediately, even if we are incredibly successful," he says.

But if orbitronics turns out to indeed be an economically feasible technology to manufacture, it will be a boon to the industry to stick with silicon, Zhang says. "There is a huge, huge investment in processing silicon," he says. "We don't want to switch overnight to a new material."

David Orenstein is the Communications and Public Relations Manager for the School of Engineering.

####


Editor Note: The study, "Orbitronics: The Intrinsic Orbital Current in p-Doped Silicon," appears in the Aug. 1 online edition of Physical Review Letters at prl.aps.org.

Relevant Web URLs:
S.C.Zhang Group
IBM-Stanford Spintronic Science and Applications Center
Physical Review Letters

Contact:
Mark Shwartz
Stanford News Service
(650) 736-2245
davidjo@stanford.edu

Comment:
Andrei Bernevig
Department of Physics
(650) 724-8054

Copyright © Stanford University

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 News Press

Possible Futures

Global Nano-Enabled Packaging Market For Food and Beverages Will Reach $15.0 billion in 2020 May 26th, 2015

Simulations predict flat liquid May 21st, 2015

Nature inspires first artificial molecular pump: Simple design mimics pumping mechanism of life-sustaining proteins found in living cells May 19th, 2015

NNCO and Museum of Science Fiction to Collaborate on Nanotechnology and 3D Printing Panels at Awesome Con May 19th, 2015

Chip Technology

One step closer to a single-molecule device: Columbia Engineering researchers first to create a single-molecule diode -- the ultimate in miniaturization for electronic devices -- with potential for real-world applications May 25th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Defects can 'Hulk-up' materials: Berkeley lab study shows properly managed damage can boost material thermoelectric performances May 20th, 2015

Nanoelectronics

One step closer to a single-molecule device: Columbia Engineering researchers first to create a single-molecule diode -- the ultimate in miniaturization for electronic devices -- with potential for real-world applications May 25th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Random nanowire configurations increase conductivity over heavily ordered configurations May 16th, 2015

Announcements

Global Nano-Enabled Packaging Market For Food and Beverages Will Reach $15.0 billion in 2020 May 26th, 2015

Dr.Theivasanthi Slashes the Price of Graphene Heavily: World first & lowest price – Nano-price (30 USD / kg) of graphene by nanotechnologist May 26th, 2015

Fine-tuned molecular orientation is key to more efficient solar cells May 26th, 2015

DNA Double Helix Does Double Duty in Assembling Arrays of Nanoparticles: Synthetic pieces of biological molecule form framework and glue for making nanoparticle clusters and arrays May 25th, 2015

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