Featured Research

from universities, journals, and other organizations

'Incoherent excitations' govern key phase of superconductor behavior

Date:
October 15, 2010
Source:
University of British Columbia
Summary:
Physicists have found that high-temperature superconductivity in copper oxides is linked to what they term "incoherent excitations" -- a discovery that sheds light on the electronic response of these materials before they become superconducting.

New research by UBC physicists indicates that high-temperature superconductivity in copper oxides is linked to what they term 'incoherent excitations'--a discovery that sheds light on the electronic response of these materials before they become superconducting.

The study marks the first time researchers have been able to directly measure when electrons in a super conductor behave as independent well-defined particles, and when they evolve into ill-defined many-body entities.

"We've never been able to directly quantify the nature of electron behaviour within these materials across the entire phase diagram--the transition from non-superconducting to superconducting behaviour," says Associate Professor Andrea Damascelli, Canada Research Chair in Electronic Structure of Solids with the Department of Physics and Astronomy.

"A combination of advanced spectroscopic techniques, and access to very pure cuprate crystals produced at UBC have allowed us to measure what's going on below the surface of a high-temperature superconducting material through the entire progression of different phases."

The paper, the first out of the newly created Quantum Matter Institute at UBC in collaboration with researchers from the Advanced Light Source at Lawrence Berkeley National Laboratory, was published this week in the journal Nature Physics.

Cuprates normally act as insulators but become superconductors when electrons are removed--a process known as 'doping' holes into the material. Physicists consider a material optimally doped when it achieves superconductivity at the highest, most accessible temperature. A material is 'underdoped' when its level of doping is less than the level that maximizes the superconducting temperature.

A central debate in the field has focused on whether high-temperature superconductivity--the ability to conduct electricity without resistance at record high temperatures--emerges from a fluid of individual Fermi liquid quasiparticles (the electron-like entities 'dressed' by the interactions with their surrounding that give rise to conventional low-temperature superconductivity), or is instead a property connected to the physics of 'strongly-correlated' Mott insulators, in which many-body electron behavior wipes quasiparticles completely out of existence.

Damascelli's team was able to measure a rapid loss of quasiparticle integrity in the material's electron behavior upon entering the cuprates' underdoped phase. "This implies that some very important concepts of Fermi liquid models breakdown entering this phase, and that we'll have to look in other theoretical directions to explain superconductivity."


Story Source:

The above story is based on materials provided by University of British Columbia. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Fournier, G. Levy, Y. Pennec, J. L. McChesney, A. Bostwick, E. Rotenberg, R. Liang, W. N. Hardy, D. A. Bonn, I. S. Elfimov, A. Damascelli. Loss of nodal quasiparticle integrity in underdoped YBa2Cu3O6 x. Nature Physics, 2010; DOI: 10.1038/nphys1763

Cite This Page:

University of British Columbia. "'Incoherent excitations' govern key phase of superconductor behavior." ScienceDaily. ScienceDaily, 15 October 2010. <www.sciencedaily.com/releases/2010/10/101014144320.htm>.
University of British Columbia. (2010, October 15). 'Incoherent excitations' govern key phase of superconductor behavior. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2010/10/101014144320.htm
University of British Columbia. "'Incoherent excitations' govern key phase of superconductor behavior." ScienceDaily. www.sciencedaily.com/releases/2010/10/101014144320.htm (accessed July 29, 2014).

Share This




More Matter & Energy News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Stranded Whale Watching Boat Returns to Boston

Stranded Whale Watching Boat Returns to Boston

Reuters - US Online Video (July 29, 2014) Passengers stuck overnight on a whale watching boat return safely to Boston. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Baluchistan Mining Eyes an Uncertain Future

Baluchistan Mining Eyes an Uncertain Future

AFP (July 29, 2014) Coal mining is one of the major industries in Baluchistan but a lack of infrastructure and frequent accidents mean that the area has yet to hit its potential. Duration: 01:58 Video provided by AFP
Powered by NewsLook.com
Easier Nuclear Construction Promises Fall Short

Easier Nuclear Construction Promises Fall Short

AP (July 29, 2014) The U.S. nuclear industry started building its first new plants using prefabricated Lego-like blocks meant to save time and prevent the cost overruns that crippled the sector decades ago. So far, it's not working. (July 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins