Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Pinning Down Superconductivity to a Single Layer

This graphic shows the inside of the molecular beam epitaxy chamber where thin films are built layer by layer, showing an artists rendition of the film synthesis process.
This graphic shows the inside of the molecular beam epitaxy chamber where thin films are built layer by layer, showing an artists rendition of the film synthesis process.

Abstract:
Findings may lead to precision engineering of superconducting thin films for electronic devices

Pinning Down Superconductivity to a Single Layer

Upton, NY | Posted on October 30th, 2009

Using precision techniques for making superconducting thin films layer-by-layer, physicists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have identified a single layer responsible for one such material's ability to become superconducting, i.e., carry electrical current with no energy loss. The technique, described in the October 30, 2009, issue of Science, could be used to engineer ultrathin films with "tunable" superconductivity for higher-efficiency electronic devices.

"We wanted to answer a fundamental question about such films," said Brookhaven physicist and the group leader Ivan Bozovic. "Namely: How thin can the film be and still retain high-temperature superconductivity?"

The thinner the material (and the higher its transition temperature to a superconductor), the greater its potential for applications where the superconductivity can be controlled by an external electric field. "This type of control is difficult to achieve with thicker films, because an electric field does not penetrate into metals more than a nanometer or so," Bozovic explained.

To explore the limits of thinness, Bozovic's group synthesized a series of films based on the high-temperature superconducting cuprates (copper-oxides) materials that carry current with no energy loss when cooled below a certain transition temperature (Tc). Since zinc is known to suppress the superconductivity in these materials, the scientists systematically substituted a small amount of zinc into each of the copper-oxide layers. Any layer where the zinc's presence had a suppressing effect would be clearly identified as essential to superconductivity in the film.

"Our measurements showed that the zinc doping had essentially no effect, except when placed in a single, well-defined layer. When the zinc was in that layer, the superconductivity was dramatically suppressed," Bozovic said.

The material studied by Bozovic's team was unusual in that it consists of layers of two materials, one metallic and one insulating, that are not superconductors on their own, but rather exhibit superconductivity at the interface between them.

The layer identified as essential to the superconductivity by the zinc-substitution experiment represents the second copper-oxide layer away from the interface. The scientists found that the presence of zinc had no effect on the transition temperature at which superconductivity sets in, about 32 kelvin (-241 Celsius), except when placed in that particular layer. In the latter case, the scientists observed a dramatic drop in the transition temperature to 18 kelvin (-255 Celsius). The reduction in transition temperature provides a clear indication that that particular layer is the "hot" one responsible for the relatively high temperature at which superconductivity normally sets in for this material.

"We now have a clean experimental proof that high-temperature superconductivity can exist, undiminished, in a single copper-oxide layer," Bozovic said. "This piece of information gives important input to our theoretical understanding of this phenomenon."

Bozovic explained that, in the material he studied, the electrons required for superconductivity actually come from the metallic material below the interface. They leak into the insulating material above the interface and achieve the critical level in that second copper-oxide layer.

But in principle, he says, there are other ways to achieve the same concentration of electrons in that single layer, for example, by doping achieved by applying electric fields. That would result in high-temperature superconductivity in a single copper-oxide layer measuring just 0.66 nanometers.

From a practical viewpoint, this discovery opens a path toward the fabrication of electronic devices with modulated, or tunable, superconducting properties which can be controlled by electric or magnetic fields.

"Electronic devices already consume a large fraction of our electricity usage and this is growing fast." Bozovic continued. "Clearly, we will need less-power hungry electronics in the future." Superconductors, which operate without energy loss particularly those that operate at warmer, more-practical temperatures may be one way to go.

Bozovic's layer-by-layer synthesis method and ability to strategically alter individual layers' composition might also be used to explore and possibly control other electronic phenomena and properties that emerge at the interfaces between layered materials.

This research was funded by the DOE Office of Science.

####

About Brookhaven National Laboratories
One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

For more information, please click here

Contacts:
Karen McNulty Walsh
(631) 344-8350

Mona S. Rowe
(631) 344-5056

Copyright © Brookhaven National Laboratories

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

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Physics

How a tetrahedral substance can be more symmetrical than a spherical atom: A new type of symmetry September 14th, 2018

Ultracold atoms used to verify 1963 prediction about 1D electrons: Rice University, University of Geneva study focuses on theory that's increasingly relevant to chipmakers September 5th, 2018

Thin films

Laser sintering optimized for printed electronics: New study sheds (laser) light on the best means of laying down thin-film circuitry September 13th, 2018

Carbon in color: First-ever colored thin films of nanotubes created: A method developed at Aalto University, Finland, can produce large quantities of pristine single-walled carbon nanotubes in select shades of the rainbow; the secret is a fine-tuned fabrication process -- and a s August 29th, 2018

Stress-free ALD from Picosun August 28th, 2018

Govt.-Legislation/Regulation/Funding/Policy

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Researchers managed to prevent the disappearing of quantum information September 14th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

Could a demon help to create a quantum computer? Physicists implement a version of Maxwell's famous thought experiment for reducing entropy September 5th, 2018

Possible Futures

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

Chip Technology

Researchers managed to prevent the disappearing of quantum information September 14th, 2018

New devices based on rust could reduce excess heat in computers: Physicists explore long-distance information transmission in antiferromagnetic iron oxide September 14th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

How a tetrahedral substance can be more symmetrical than a spherical atom: A new type of symmetry September 14th, 2018

Nanoelectronics

How a tetrahedral substance can be more symmetrical than a spherical atom: A new type of symmetry September 14th, 2018

Laser sintering optimized for printed electronics: New study sheds (laser) light on the best means of laying down thin-film circuitry September 13th, 2018

September 5th, 2018

Rice U. lab probes molecular limit of plasmonics: Optical effect detailed in organic molecules with fewer than 50 atoms September 5th, 2018

Discoveries

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 2018

New photonic chip promises more robust quantum computers September 14th, 2018

Announcements

NUS researchers invent new test kit for quick, accurate and low-cost screening of diseases: Test results are denoted by a color change and could be further analyzed by a smartphone app, making it attractive as a point-of-care diagnostic device September 19th, 2018

Silver nanoparticles are toxic for aquatic organisms: A research team at the UPV/EHU-University of the Basque Country has analysed how zebrafish are affected in the long term by exposure to silver particles September 19th, 2018

Leti Announces EU Project to Develop Powerful, Inexpensive Sensors with Photonic Integrated Circuits: REDFINCH Members Initially Targeting Applications for Gas Detection and Analysis For Refineries & Petrochemical Industry and Protein Analysis for Dairy Industry September 19th, 2018

Researchers develop microbubble scrubber to destroy dangerous biofilms September 19th, 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