Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hidden order found in cuprates may help explain superconductivity

13.02.2004


Like the delicate form of an icicle defying gravity during a spring thaw, patterns emerge in nature when forces compete. Scientists at the University of Illinois at Urbana-Champaign have found a hidden pattern in cuprate (copper-containing) superconductors that may help explain high-temperature superconductivity.




Superconductivity, the complete loss of electrical resistance in some materials, occurs at temperatures near absolute zero. First observed in 1911 by Dutch physicist Heike Kamerlingh Onnes, the mechanism of superconductivity remained unexplained until 1957, when Illinois physicists John Bardeen, Leon Cooper, and J. Robert Schrieffer determined that electrons, normally repulsive, could form pairs and move in concert in superconducting materials below a certain critical temperature.

For more than a decade, scientists have been baffled by superconductivity in the copper oxides, which occurs at liquid-nitrogen temperatures and does not seem to behave according to standard BCS theory. A tantalizing goal, which would have enormous implications for electronics and power distribution, is to achieve superconductivity at room temperature. A large piece of the puzzle has been to understand how the coherent dance of electrons that gives rise to superconductivity changes when the material is heated.


In a paper to appear in the journal Science, as part of the Science Express Web site, on Feb. 12, researchers at Illinois show that when heated, the orderly superconducting dance of electrons is replaced, not by randomness as might be assumed, but by a distinct type of movement in which electrons organize into a checkerboard pattern. The experimental findings imply that the two types of electron organization, coherent motion and spatial organization, are in competition in the copper oxides -- an idea that may break the logjam on the mystery of high-temperature superconductivity.

"Heating a normal superconductor above its critical temperature results in a normal metallic behavior, but heating a high-temperature superconductor above its critical temperature results in a non-metallic state of electrons called the pseudogap state," said physics professor Ali Yazdani, a Willett Faculty Scholar at Illinois and senior author of the paper. "We have examined for the first time the motion of electrons in this mysterious pseudogap state on the nanometer scale."

Yazdani and graduate students Michael Vershinin and Shashank Misra used a scanning tunneling microscope to map electron waves in cuprate superconductors at high temperatures.

"Comparing maps of electron waves in both the superconducting and the pseudogap state, we have found that electrons in the pseudogap state organize into a checkerboard pattern," Yazdani said. "This pattern appears to be the result of competing forces felt by the electrons, such as Coulomb repulsion because of their charge and magnetic interactions resulting from their spins."

Regardless of the specific cause of the local ordering, "our experimental observations provide new constraints on the potential theoretical description of the pseudogap state in the cuprates and how it transforms into superconductivity when we cool the cuprate samples," Yazdani said.

Pattern formation of electron waves in high-temperature copper-oxide superconductors has long been anticipated theoretically, and Illinois physics professor Eduardo Fradkin contributed to the theoretical work. However, the experimental discovery of such pattern formation was made possible by a new generation of STM designed by Yazdani’s group to operate at temperatures above the superconducting transition temperature.

Collaborators on the pattern-formation project also included colleagues at the Central Research Institute of Electric Power Industry in Japan.


The National Science Foundation, Office of Naval Research and the U.S. Department of Energy funded the work.

James E. Kloeppel | UIUC

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>