Welcome!

News Feed Item

Breakthrough in Superconductivity - Université de Sherbrooke Physicists Put an End to 20 Years of Debate

SHERBROOKE, QC, Feb. 14, 2014 /CNW Telbec/ - Three physicists at the Université de Sherbrooke led an international team to first direct measurement of the critical magnetic field in cuprates, the most promising materials for superconductivity. This breakthrough resolves an enigma that has baffled researchers for 20 years and clears the way for major advances. The study is published in the prestigious journal Nature Communications.

A Dream Destination: Superconductivity at Ambient Temperature

When some materials are cooled to very low temperature, barely above absolute zero (-273 °C), they become superconductors, and their electrical and magnetic properties change radically. They acquire a nearly magical property: they carry electricity perfectly, without any energy loss.

The most promising superconducting materials are copper oxides, also called cuprates. They are, at present, the materials that become superconductors at the highest temperature, specifically -150 °C, which is halfway between absolute zero and ambient temperature.

So, for now, these materials must still be cooled down to extremely low temperatures before they become superconducting. "If this state could persist at ambient temperature, it would profoundly transform our technological world," maintains Louis Taillefer, holder of the Canada Research Chair in Quantum Materials and the study's senior investigator. The transmission of electricity around the world would be radically changed, for example. "This great dream will become possible when scientists understand how to increase the maximum value of the critical temperature by a factor of two or more."

The team has just identified one of the main mechanisms limiting the critical temperature of cuprates, which opens a new direction in determining how to increase it.

A Million Times Stronger than the Earth's Magnetic Field

In addition to their critical temperature, another fundamental property of superconductors is their critical magnetic field. What is its value in cuprates?

In order to measure the critical field of cuprates, the team investigated their capacity to conduct heat. A material's heat conductivity turns out to be very sensitive to the onset of superconductivity. The very first direct measurement of this critical field in cuprates was made possible as the result of a novel approach developed by the group of researchers working on the physics of quantum materials at the Université de Sherbrooke.

"The key to our discovery," says Nicolas Doiron-Leyraud, "was developing equipment at Sherbrooke that can make such measurements under very strong magnetic fields." The team then traveled to specialized laboratories in Tallahassee, Florida, and Grenoble, France, where magnetic fields up to 1 million times the earth's field are produced.

"Once there, we realized that it was the first time that anyone had made such an attempt, explains Gaël Grissonnanche, PhD student in physics and first author on the paper. The first measurements on the first day… and it worked!"

A Clear Signature

"The critical field's signature immediately became apparent in our data," says Nicolas Doiron-Leyraud. It was this new measurement that led the Sherbrooke group to make its major discovery. "We observed a sudden drop in the critical field below a certain concentration of electrons" explains Doiron-Leyraud. Louis Taillefer, who also directs the Quantum Materials program at the Canadian Institute for Advanced Research, puts this discovery into perspective. "For 20 years, scientists have wondered what mechanism is responsible for the drop in critical temperature when the concentration of electrons in a cuprate material drops below a certain level. Up until now, two major scenarios were in the running."

The first scenario attributes the drop to the fact that the metal - that is, the cuprate - is gradually becoming an insulator. Electrons don't move in insulators, so they can no longer form mobile pairs. The second scenario attributes the drop in critical temperature to the sudden appearance in the material of a distinct electronic phase that enters into competition with the superconductivity and weakens it.

"Since 1995, the scientific community has been strongly leaning in favor of the first scenario. Our work now unequivocally demonstrates that the second scenario is at work. That opens a whole new path for increasing the critical temperature at which superconductivity can occur: the competing phase has to be eliminated," concludes Louis Taillefer.

SOURCE Université de Sherbrooke

More Stories By PR Newswire

Copyright © 2007 PR Newswire. All rights reserved. Republication or redistribution of PRNewswire content is expressly prohibited without the prior written consent of PRNewswire. PRNewswire shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.

Latest Stories
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
In his keynote at 19th Cloud Expo, Sheng Liang, co-founder and CEO of Rancher Labs, discussed the technological advances and new business opportunities created by the rapid adoption of containers. With the success of Amazon Web Services (AWS) and various open source technologies used to build private clouds, cloud computing has become an essential component of IT strategy. However, users continue to face challenges in implementing clouds, as older technologies evolve and newer ones like Docker c...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend @CloudExpo | @ThingsExpo, June 6-8, 2017, at the Javits Center in New York City, NY and October 31 - November 2, 2017, Santa Clara Convention Center, CA. Learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
Building a cross-cloud operational model can be a daunting task. Per-cloud silos are not the answer, but neither is a fully generic abstraction plane that strips out capabilities unique to a particular provider. In his session at 20th Cloud Expo, Chris Wolf, VP & Chief Technology Officer, Global Field & Industry at VMware, will discuss how successful organizations approach cloud operations and management, with insights into where operations should be centralized and when it’s best to decentraliz...
Data is an unusual currency; it is not restricted by the same transactional limitations as money or people. In fact, the more that you leverage your data across multiple business use cases, the more valuable it becomes to the organization. And the same can be said about the organization’s analytics. In his session at 19th Cloud Expo, Bill Schmarzo, CTO for the Big Data Practice at Dell EMC, introduced a methodology for capturing, enriching and sharing data (and analytics) across the organization...
Five years ago development was seen as a dead-end career, now it’s anything but – with an explosion in mobile and IoT initiatives increasing the demand for skilled engineers. But apart from having a ready supply of great coders, what constitutes true ‘DevOps Royalty’? It’ll be the ability to craft resilient architectures, supportability, security everywhere across the software lifecycle. In his keynote at @DevOpsSummit at 20th Cloud Expo, Jeffrey Scheaffer, GM and SVP, Continuous Delivery Busine...
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
SYS-CON Events announced today that Progress, a global leader in application development, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Enterprises today are rapidly adopting the cloud, while continuing to retain business-critical/sensitive data inside the firewall. This is creating two separate data silos – one inside the firewall and the other outside the firewall. Cloud ISVs oft...
SYS-CON Events announced today that Juniper Networks (NYSE: JNPR), an industry leader in automated, scalable and secure networks, will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Juniper Networks challenges the status quo with products, solutions and services that transform the economics of networking. The company co-innovates with customers and partners to deliver automated, scalable and secure network...
In recent years, containers have taken the world by storm. Companies of all sizes and industries have realized the massive benefits of containers, such as unprecedented mobility, higher hardware utilization, and increased flexibility and agility; however, many containers today are non-persistent. Containers without persistence miss out on many benefits, and in many cases simply pass the responsibility of persistence onto other infrastructure, adding additional complexity.
SYS-CON Events announced today that CA Technologies has been named "Platinum Sponsor" of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, New York, and 21st International Cloud Expo, which will take place in November in Silicon Valley, California.
New competitors, disruptive technologies, and growing expectations are pushing every business to both adopt and deliver new digital services. This ‘Digital Transformation’ demands rapid delivery and continuous iteration of new competitive services via multiple channels, which in turn demands new service delivery techniques – including DevOps. In this power panel at @DevOpsSummit 20th Cloud Expo, moderated by DevOps Conference Co-Chair Andi Mann, panelists will examine how DevOps helps to meet th...
DevOps is being widely accepted (if not fully adopted) as essential in enterprise IT. But as Enterprise DevOps gains maturity, expands scope, and increases velocity, the need for data-driven decisions across teams becomes more acute. DevOps teams in any modern business must wrangle the ‘digital exhaust’ from the delivery toolchain, "pervasive" and "cognitive" computing, APIs and services, mobile devices and applications, the Internet of Things, and now even blockchain.
Did you know that you can develop for mainframes in Java? Or that the testing and deployment can be automated across mobile to mainframe? In his session at @DevOpsSummit at 20th Cloud Expo, Vaughn Marshall, Sr. Principal Product Owner at CA Technologies, will discuss and demo how increasingly teams are developing with agile methodologies using modern development environments and automating testing and deployments, mobile to mainframe.