Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Semiconductor could turn heat into computing power

Joseph Heremans
Joseph Heremans

Abstract:
Computers might one day recycle part of their own waste heat, using a material being studied by researchers at Ohio State University.

Semiconductor could turn heat into computing power

Columbus, OH | Posted on September 27th, 2010

The material is a semiconductor called gallium manganese arsenide. In the early online edition of Nature Materials, researchers describe the detection of an effect that converts heat into a quantum mechanical phenomenon - known as spin - in a semiconductor.

Once developed, the effect could enable integrated circuits that run on heat, rather than electricity.

This research merges two cutting-edge technologies: thermo-electricity and spintronics, explained team leaders Joseph Heremans, Ohio Eminent Scholar in Nanotechnology, and Roberto Myers, assistant professor of materials science and electrical engineering at Ohio State University.

Researchers around the world are working to develop electronics that utilize the spin of electrons to read and write data. So-called "spintronics" are desirable because in principle they could store more data in less space, process data faster, and consume less power.

Myers and Heremans are trying to combine spintronics with thermo-electronics - that is, devices that convert heat to electricity.

The hybrid technology, "thermo-spintronics," would convert heat to electron spin.

In so doing, thermo-spintronics could solve two problems for the computing industry: how to remove waste heat, and how to boost computing power without creating more heat.

"Spintronics is considered as a possible basis for new computers in part because the technology is claimed to produce no heat. Our measurements shed light on the thermodynamics of spintronics, and may help address the validity of this claim," Heremans said.

In fact, as the electronics industry tries to build smaller, denser computer circuits, a main limiting factor is the heat those circuits produce, said Myers.

"All of the computers we have now could actually run much faster than they do, but they're not allowed to - because if they did, they would fail after a short time," Myers said. "So a huge amount of money in the semiconductor industry is put toward thermal management."

In one possible use of thermo-spintronics, a device could sit atop a traditional microprocessor, and siphon waste heat away to run additional memory or computation. Myers noted that such applications are still a long way off.

The researchers studied how heat can be converted to spin polarization- an effect called the spin-Seebeck effect. It was first identified by researchers at Tohoku University and reported in a 2008 paper in the journal Nature. Those researchers detected the effect in a piece of metal, rather than a semiconductor.

The new measurements, carried out by team member Christopher Jaworski, doctoral student of mechanical engineering at Ohio State, provide the first independent verification of the effect in a semiconductor material called gallium manganese arsenide.

While gallium arsenide is a semiconductor used in cell phones today, the addition of the element manganese endows the material with magnetic properties.

Samples of this material were carefully prepared into thin single-crystal films by collaborators Shawn Mack and Professor David Awschalom at the University of California at Santa Barbara, who also assisted with interpretation of the results. Jing Yang, doctoral student of materials science and engineering at Ohio State, then processed the samples for the experiment.

In this type of material, the spins of the charges line up parallel with the orientation of the sample's overall magnetic field. So when the Ohio State researchers were trying to detect the spins of the electrons, they were really measuring whether the electrons in any particular area of the material were oriented as "spin-up" or "spin-down."

In the experiment, they heated one side of the sample, and then measured the orientations of spins on the hot side and the cool side. On the hot side, the electrons were oriented in the spin-up direction, and on the cool side, they were spin-down.

The researchers also discovered, to their own surprise, that two pieces of the material do not need to be physically connected for the effect to propagate from one to the other.

They scraped away a portion of the sample with a file, to create two pieces of material separated by a tiny gap. If the spin effect were caused by electrical conduction - that is, electrons flowing from one part of the material to the other - then the gap would block the effect from spreading. Again, they applied heat to one side.

The effect persisted.

"We figured that each piece would have its own distribution of spin-up and spin-down electrons," said Myers. "Instead, one side of the first piece was spin up, and the far side of the second piece was spin down. The effect somehow crossed the gap."

"The original spin-Seebeck detection by the Tohoku group baffled all theoreticians," Heremans added. "In this study, we've independently confirmed those measurements on a completely different material. We've proven we can get the same results as the Tohoku group, even when we take the measurements on a sample that's been separated into two pieces, so that electrons couldn't possibly pass between them."

Despite these new experiments, the origin of the spin-Seebeck effect remains a mystery.

This work was supported by the National Science Foundation, the Office of Naval Research, and the Ohio Eminent Scholar Discretionary Fund. Partial support was provided by The Ohio State University Institute for Materials Research.

####

Contacts:
Joseph Heremans
(614) 247-8869


Roberto Myers
(614) 292-8439


Written by
Pam Frost Gorder
(614) 292-9475

Copyright © Ohio State 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

News and information

Energy-efficient spin current can be controlled by magnetic field and temperature: SCMR effect simplifies the design of fundamental spintronic components August 20th, 2018

Color effects from transparent 3D printed nanostructures: New design tool automatically creates nanostructure 3D print templates for user-given colors Scientists present work at prestigious SIGGRAPH conference August 18th, 2018

UVA multidisciplinary engineering team designs technology for smart materials: The invention could lead to devices and manufactured goods, such as fabrics, that can dynamically regulate between thermally insulating and cooling August 17th, 2018

Smallest transistor worldwide switches current with a single atom in solid electrolyte: Milestone of energy efficiency in information technology -- Publication in Advanced Materials August 17th, 2018

Govt.-Legislation/Regulation/Funding/Policy

Color effects from transparent 3D printed nanostructures: New design tool automatically creates nanostructure 3D print templates for user-given colors Scientists present work at prestigious SIGGRAPH conference August 18th, 2018

UVA multidisciplinary engineering team designs technology for smart materials: The invention could lead to devices and manufactured goods, such as fabrics, that can dynamically regulate between thermally insulating and cooling August 17th, 2018

Scientists turn to the quantum realm to improve energy transportation August 17th, 2018

Research brief: UMN researchers use green gold to rapidly detect and identify harmful bacteria August 15th, 2018

Possible Futures

Energy-efficient spin current can be controlled by magnetic field and temperature: SCMR effect simplifies the design of fundamental spintronic components August 20th, 2018

Color effects from transparent 3D printed nanostructures: New design tool automatically creates nanostructure 3D print templates for user-given colors Scientists present work at prestigious SIGGRAPH conference August 18th, 2018

Novel nanoparticle-based approach detects and treats oral plaque without drugs August 17th, 2018

UVA multidisciplinary engineering team designs technology for smart materials: The invention could lead to devices and manufactured goods, such as fabrics, that can dynamically regulate between thermally insulating and cooling August 17th, 2018

Chip Technology

Energy-efficient spin current can be controlled by magnetic field and temperature: SCMR effect simplifies the design of fundamental spintronic components August 20th, 2018

Smallest transistor worldwide switches current with a single atom in solid electrolyte: Milestone of energy efficiency in information technology -- Publication in Advanced Materials August 17th, 2018

Scientists create antilaser for ultracold atoms condensate August 16th, 2018

Flipping the switch on supramolecular electronics August 14th, 2018

Announcements

Energy-efficient spin current can be controlled by magnetic field and temperature: SCMR effect simplifies the design of fundamental spintronic components August 20th, 2018

Color effects from transparent 3D printed nanostructures: New design tool automatically creates nanostructure 3D print templates for user-given colors Scientists present work at prestigious SIGGRAPH conference August 18th, 2018

UVA multidisciplinary engineering team designs technology for smart materials: The invention could lead to devices and manufactured goods, such as fabrics, that can dynamically regulate between thermally insulating and cooling August 17th, 2018

Smallest transistor worldwide switches current with a single atom in solid electrolyte: Milestone of energy efficiency in information technology -- Publication in Advanced Materials August 17th, 2018

Military

Biomimetic micro/nanoscale fiber reinforced composites August 10th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

UMBC researchers develop nanoparticles to reduce internal bleeding caused by blast trauma July 13th, 2018

Carbon is the new black: Researchers use carbon nanotubes to develop clothing that can double as batteries July 10th, 2018

Energy

Smallest transistor worldwide switches current with a single atom in solid electrolyte: Milestone of energy efficiency in information technology -- Publication in Advanced Materials August 17th, 2018

Scientists turn to the quantum realm to improve energy transportation August 17th, 2018

Particles pull last drops of oil from well water: Rice University engineers find nanoscale solution to 'produced water' problem August 15th, 2018

CTI Materials drives nano commercialization with it's patented surfactant free nanoparticle dispersions August 15th, 2018

Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records

Scientists turn to the quantum realm to improve energy transportation August 17th, 2018

Research brief: UMN researchers use green gold to rapidly detect and identify harmful bacteria August 15th, 2018

Particles pull last drops of oil from well water: Rice University engineers find nanoscale solution to 'produced water' problem August 15th, 2018

Breaking down the Wiedemann-Franz law: In a study exploring the coupling between heat and particle currents in a gas of strongly interacting atoms, physicists at ETH Zurich find puzzling behaviours August 10th, 2018

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project