Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Key Advance in Understanding ‘Pseudogap’ Phase in High-Tc Superconductors

This pattern shows the tunneling potential of electrons on oxygen atoms “north” and “east” of each copper atom (shown embedded in the pattern) in the copper-oxide layer of a superconductor in the pseudogap phase. On oxygen atoms north of each copper, the tunneling potential is strong, as indicated by the brightness of the yellow patches forming lines in the north-south direction. On oxygen atoms east of each copper, the tunneling potential is weaker, indicated by less intense yellow lines in the east-west direction. This apparent broken symmetry may help scientists understand the pseudogap phase of copper-oxide superconductors.
This pattern shows the tunneling potential of electrons on oxygen atoms “north” and “east” of each copper atom (shown embedded in the pattern) in the copper-oxide layer of a superconductor in the pseudogap phase. On oxygen atoms north of each copper, the tunneling potential is strong, as indicated by the brightness of the yellow patches forming lines in the north-south direction. On oxygen atoms east of each copper, the tunneling potential is weaker, indicated by less intense yellow lines in the east-west direction. This apparent broken symmetry may help scientists understand the pseudogap phase of copper-oxide superconductors.

Abstract:
May lead to ways to overcome barrier to room-temperature superconductivity in copper-oxides

Key Advance in Understanding ‘Pseudogap’ Phase in High-Tc Superconductors

Upton, NY | Posted on July 16th, 2010

Scientists have been trying for some 20 years to understand why the low temperature at which copper-oxide superconductors carry current with no resistance can't be increased to be closer to room temperature. Recently, scientists have focused on trying to understand and control an electronic phase called the "pseudogap" phase, which is non-superconducting and is observed at a temperature above the superconducting phase. But what form of electronic order (if any) characterizes the pseudogap phase has remained a frustrating and challenging mystery.

Now scientists have discovered a fundamental difference in how electrons behave at the two distinct oxygen-atom sites within each copper-oxide unit, which appears to be a specific property of the non-superconducting pseudogap phase. The research — described in the July 15, 2010, issue of Nature — may lead to new approaches to understanding the pseudogap phase, which has been hypothesized as a key hurdle to achieving room-temperature superconductivity.

"Many people consider the disappearance of superconductivity that occurs when the pseudogap phase emerges as an indication that the pseudogap is the killer of room temperature superconductivity in the copper-oxides," said study leader Séamus Davis, director of the Center for Emergent Superconductivity at the U.S. Department of Energy's Brookhaven National Laboratory and the J.D. White Distinguished Professor of Physical Sciences at Cornell University. "Detecting a difference in electron behavior at the two oxygen sites within each copper-oxide unit at the pseudogap energy may be a very significant step toward identifying exactly what the pseudogap state is and how it affects superconductivity."

To identify the change in electronic behavior, Davis worked with other physicists from Binghamton University, Cornell University, Brookhaven, the University of Tokyo, the Advanced Institute of Science and Technology in Korea, the RIKEN laboratory in Japan, and Japan's Institute of Advanced Industrial Science and Technology. Using a technique known as spectroscopic imaging scanning tunneling microscopy, they measured the relative ease with which electrons could jump from the surface at each individual copper and oxygen site to the tip of the microscope needle. New theoretical approaches pioneered by Michael Lawler of Binghamton and Eun-Ah Kim of Cornell helped the group understand the electron behavior.

Across the entire copper-oxide crystal, the scientists found a remarkable difference in the electronic states associated with the mysterious pseudogap phase: The number of electrons able to "tunnel" to the microscope tip differed depending on the position of the oxygen atom relative to the copper atom. "Picture the copper atom at the center of the unit, with one oxygen to the ‘north' and one to the ‘east,' and this whole unit repeating itself over and over across the copper-oxide layer," Davis said. "In every single copper-oxide unit, the tunneling ability of electrons from the northern oxygen atom was different from that of the eastern oxygen."

The discovery of this asymmetrical behavior could be a breakthrough in understanding and controlling high-temperature superconductors because, historically, uncovering the reductions in symmetry responsible for other states of matter has led to huge advances in understanding and achieving control over those states. For example, discovery of the symmetries broken in liquid crystals eventually led to their control and everyday use in liquid crystal displays (LCDs).

The scientists will pursue their pseudogap research, first by looking for a similar broken symmetry in other copper-oxide superconductors. They will also try to determine: how the directional asymmetry in electronic behavior affects the ability of electrons to flow through the system; how that directional dependence might inhibit superconductivity; and eventually, how this might be overcome at temperatures warm enough to make high-temperature superconducting technologies practical.

"The ultimate goal is to discover or create materials that can act as superconductors, to carry electric current with no energy loss, at room temperature," Davis said.

Conventional superconductors, and even the known "high-temperature" varieties, must all be cooled well below freezing temperatures — some near absolute zero, or -273°C — to operate without energy loss. That requires using coolants like liquid helium or nitrogen, which makes them impractical for everyday uses.

"Developing superconductors that operate without the need for coolants would be transformational," said Davis. "Such materials would greatly improve the efficiency of energy-distribution systems, saving enormous amounts of money and updating the electrical grid to meet the needs of the 21st Century."

Through its Center for Emergent Superconductivity, one of 46 new multi-million-dollar Energy Frontier Research Centers (EFRCs) established last year by the DOE Office of Science, Brookhaven Lab is playing a leading role in addressing this challenge. Office of Science funding for that center supported Brookhaven's contribution to the current research. Theoretical studies were supported by the National Science Foundation. Additional funding was provided by the U.S. Army Research Office and the University of British Columbia.

####

About Brookhaven National Laboratory
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

Peter Genzer
(631) 344-3174

Copyright © Brookhaven National Laboratory

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

Controlled Release of Anticorrosive Materials in Spot by Nanocarriers May 27th, 2015

Production of Copper Cobaltite Nanocomposites with Photocatalytic Properties in Iran May 27th, 2015

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

Govt.-Legislation/Regulation/Funding/Policy

Researchers find the 'key' to quantum network solution May 25th, 2015

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

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

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

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

Academic/Education

SUNY Poly CNSE and NIOSH Launch Federal Nano Health and Safety Consortium: May 20th, 2015

New JEOL E-Beam Lithography System to Enhance Quantum NanoFab Capabilities May 6th, 2015

FEI Partners With the George Washington University to Equip New Science & Engineering Hall: Suite of new high-performance microscopes will be used for cutting-edge experiments at GW’s new research facility April 29th, 2015

Renishaw Raman systems used to study 2D materials at Boston University, Massachusetts, USA. April 28th, 2015

Discoveries

Production of Copper Cobaltite Nanocomposites with Photocatalytic Properties in Iran May 27th, 2015

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

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

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

Announcements

Controlled Release of Anticorrosive Materials in Spot by Nanocarriers May 27th, 2015

Production of Copper Cobaltite Nanocomposites with Photocatalytic Properties in Iran May 27th, 2015

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

Research partnerships

Supercomputer unlocks secrets of plant cells to pave the way for more resilient crops: IBM partners with University of Melbourne and UQ May 21st, 2015

Taking control of light emission: Researchers find a way of tuning light waves by pairing 2 exotic 2-D materials May 20th, 2015

Efficiency record for black silicon solar cells jumps to 22.1 percent: Aalto University's researchers improved their previous record by over 3 absolute percents in cooperation with Universitat Politècnica de Catalunya May 18th, 2015

Organic nanoparticles, more lethal to tumors: Carbon-based nanoparticles could be used to sensitize cancerous tumors to proton radiotherapy and induce more focused destruction of cancer cells, a new study shows May 18th, 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