Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Study Gives Lowdown On High-Temperature Superconductivity


A new study by theoretical physicists at the University of Toronto and the University of California at Los Angeles (ULCA) could bring scientists one step closer to the dream of a superconductor that functions at room temperature, rather than the frigid temperatures more commonly found in deep space.

Microscopic image of a ceramic superconductor
Image: Michael W. Davidson
Florida State University

The findings, which appear in the March 4 issue of the journal Nature, identify three factors that explain a perplexing pattern in the temperatures at which multi-layered ceramic materials become superconductors. The study could advance research in medical imaging, electrical power transmission and magnetically levitating trains. Its authors are U of T physics professor Hae-Young Kee and post-doctoral fellow Klaus Völker, and Professor Sudip Chakravarty of UCLA’s physics and astronomy department.

Superconductivity is a phenomenon that occurs when certain metals are cooled to near absolute zero, a temperature equivalent to zero degrees Kelvin (K), -273 C or -459 F. In ceramic materials, the phenomenon appears at about 100K. At a so-called critical temperature—that varies depending on the number of layers within the ceramic substance—the material becomes capable of conducting electricity without any energy loss.

Despite the value of such an efficient system, the supercooling—usually done with liquid nitrogen or liquid helium—makes superconductors impractical for many applications. “A room temperature superconductor would be a revolution, but even a superconductor with a higher critical temperature would have extremely important implications for multiple industries,” says Kee, who holds the Canada Research Chair in Theoretical Condensed Matter Physics.

Materials scientists have developed a group of “high-temperature” superconductors made with layers of copper oxides sandwiched between insulating filler material. This material reaches critical temperatures in the range of roughly 130K—the highest know critical temperatures to date. Previous studies on superconductors have established that while the critical temperature rises as the number of layers increase from one to three, it then drops off. By the time the number of layers rises to seven, the critical temperature has fallen below that of the single-layer superconductor.

Scientists have previously suggested that the critical temperature increase between one- and three-layered materials is due to the ability of electron pairs to tunnel between the layers of superconducting material.

Now, Kee and her colleagues have identified the factors that combine with a mechanism—known as the competing order—that lowers a superconductor’s critical temperature in materials with more than three layers. That “competing order,” in turn, is dependent on an uneven distribution of electrons, resulting in a charge imbalance between the material’s multiple layers. Kee and her colleagues are the first group to put these three factors—the tunnelling, the competing order and the charge imbalance—together.

“If we can find a way to affect the charge imbalance, we could suppress the competing order and develop superconducting materials with higher and higher critical temperatures,” says Kee. “And if you can push the superconducting temperature higher, then it will become much cheaper to apply this technology.”

The research was funded by the U.S. National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, the Canadian Institute of Advanced Research, the Canada Research Chairs program and the Alfred P. Sloan Foundation.


Klaus Völker
Department of Physics
416-333-5633 (cell)

Hae-Young Kee (available March 4)
Department of Physics

Nicolle Wahl
U of T Public Affairs

Nicolle Wahl | University of Toronto
Further information:

More articles from Physics and Astronomy:

nachricht 'Frequency combs' ID chemicals within the mid-infrared spectral region
16.03.2018 | American Institute of Physics

nachricht Fraunhofer HHI have developed a novel single-polarization Kramers-Kronig receiver scheme
16.03.2018 | Fraunhofer-Institut für Nachrichtentechnik, Heinrich-Hertz-Institut, HHI

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: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>