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
"This is specifically designed to accommodate some of the needs for high availability and failover in a network managed system for the major Korean corporations," stated Thomas Masters, Managing Director at InfranicsUSA, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
@DevOpsSummit at Cloud taking place June 6-8, 2017, at Javits Center, New York City, is co-located with the 20th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long developm...
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.
Infrastructure is widely available, but who’s managing inbound/outbound traffic? Data is created, stored, and managed online – who is protecting it and how? In his session at 19th Cloud Expo, Jaeson Yoo, SVP of Business Development at Penta Security Systems Inc., discussed how to keep any and all infrastructure clean, safe, and efficient by monitoring and filtering all malicious HTTP/HTTPS traffic at the OSI Layer 7. Stop attacks and web intruders before they can enter your network.
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smar...
Get deep visibility into the performance of your databases and expert advice for performance optimization and tuning. You can't get application performance without database performance. Give everyone on the team a comprehensive view of how every aspect of the system affects performance across SQL database operations, host server and OS, virtualization resources and storage I/O. Quickly find bottlenecks and troubleshoot complex problems.
Regulatory requirements exist to promote the controlled sharing of information, while protecting the privacy and/or security of the information. Regulations for each type of information have their own set of rules, policies, and guidelines. Cloud Service Providers (CSP) are faced with increasing demand for services at decreasing prices. Demonstrating and maintaining compliance with regulations is a nontrivial task and doing so against numerous sets of regulatory requirements can be daunting task...
Without a clear strategy for cost control and an architecture designed with cloud services in mind, costs and operational performance can quickly get out of control. To avoid multiple architectural redesigns requires extensive thought and planning. Boundary (now part of BMC) launched a new public-facing multi-tenant high resolution monitoring service on Amazon AWS two years ago, facing challenges and learning best practices in the early days of the new service. In his session at 19th Cloud Exp...
"We build IoT infrastructure products - when you have to integrate different devices, different systems and cloud you have to build an application to do that but we eliminate the need to build an application. Our products can integrate any device, any system, any cloud regardless of protocol," explained Peter Jung, Chief Product Officer at Pulzze Systems, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
The cloud promises new levels of agility and cost-savings for Big Data, data warehousing and analytics. But it’s challenging to understand all the options – from IaaS and PaaS to newer services like HaaS (Hadoop as a Service) and BDaaS (Big Data as a Service). In her session at @BigDataExpo at @ThingsExpo, Hannah Smalltree, a director at Cazena, provided an educational overview of emerging “as-a-service” options for Big Data in the cloud. This is critical background for IT and data professionals...
Internet of @ThingsExpo has announced today that Chris Matthieu has been named tech chair of Internet of @ThingsExpo 2017 New York The 7th Internet of @ThingsExpo will take place on June 6-8, 2017, at the Javits Center in New York City, New York. Chris Matthieu is the co-founder and CTO of Octoblu, a revolutionary real-time IoT platform recently acquired by Citrix. Octoblu connects things, systems, people and clouds to a global mesh network allowing users to automate and control design flo...
You are moving to the Cloud. The question is not if, it’s when. Now that your competitors are in the cloud and lapping you, your “when” better hurry up and get here. But saying and doing are two different things. In his session at @DevOpsSummit at 18th Cloud Expo, Robert Reeves, CTO of Datical, explained how DevOps can be your onramp to the cloud. By adopting simple, platform independent DevOps strategies, you can accelerate your move to the cloud. Spoiler Alert: He also makes sure you don’t...
President Obama recently announced the launch of a new national awareness campaign to "encourage more Americans to move beyond passwords – adding an extra layer of security like a fingerprint or codes sent to your cellphone." The shift from single passwords to multi-factor authentication couldn’t be timelier or more strategic. This session will focus on why passwords alone are no longer effective, and why the time to act is now. In his session at 19th Cloud Expo, Chris Webber, security strateg...
"We are an all-flash array storage provider but our focus has been on VM-aware storage specifically for virtualized applications," stated Dhiraj Sehgal of Tintri in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Redis is not only the fastest database, but it has become the most popular among the new wave of applications running in containers. Redis speeds up just about every data interaction between your users or operational systems. In his session at 18th Cloud Expo, Dave Nielsen, Developer Relations at Redis Labs, shared the functions and data structures used to solve everyday use cases that are driving Redis' popularity.