New Understanding For Superconductivity At High Temperatures
2008 01 13
An international research team has discovered that a magnetic field can interact with the electrons in a superconductor in ways never before observed. Andrea D. Bianchi, the lead researcher from the Université de Montréal, explains in the January 11 edition of the journal Science what he discovered in an exceptional compound of metals -- a combination of cobalt, indium and a rare earth -- that loses its resistance when cooled to just a couple of degrees above absolute zero.
Superconductivity is a phenomenon which occurs in certain materials and which manifests itself by a complete loss of electrical resistance. An important area in the study of superconductors is how they respond to magnetic fields. Besides their obvious relevance to practical applications, such studies are an ideal way to obtain a deeper understanding of the fundamental aspects of superconductivity.
When subjected to a magnetic field, most superconductors will generate vortices (electric tornadoes) which confine them in tubes of magnetic flux. Such vortices have been described by a model for which Alexei Abrikosov and Vitaly Ginsburg received a Nobel Prize in 2003. However, the results obtained by Eskildsen and his colleagues reveal a radical departure from the usual behavior.
“Even in materials such as the high-temperature or heavy-fermion superconductors, where we do not presently understand the microscopic nature of the superconducting state, the Abrikosov-Ginzburg-Landau picture has, for more than 50 years, provided us with a phenomenological description of the vortices,” Eskildsen said. “But in CeCoIn5, as our measurements demonstrate, this paradigm breaks down, forcing us to rethink our understanding of superconductivity.”
The discovery of superconductivity in certain ceramic materials at temperatures as high as 140K (-208 degrees Fahrenheit), well above the boiling point of liquid nitrogen, opened up new possibilities for applications. Superconductors are currently being used or developed for a wide range of applications including electric power transmission, ship propulsion motors, magnetically levitated trains, magnets for medical imaging, and digital filters for high-speed communications.
"This discovery sharpens our understanding of what, literally, holds the world together and brings physicists one step closer to getting a grip on superconductivity at high temperatures. Until now, physicists were going around in circles, so this discovery will help to drive new understanding," said Prof. Bianchi, who was recruited to UdeM as a Canada Research Chair in Novel Materials for Spintronics last fall and performed his experiments at the Paul Scherrer Institute in Switzerland, in collaboration with scientists from ETH Zurich, the University of Notre Dame, the University of Birmingham, U.K., the Los Alamos National Laboratory and the Brookhaven National Laboratory.
Magnetic tornado that grows stronger
Using the Swiss Spallation Neutron Source (SINQ), Prof. Bianchi and his team cooled a single-crystal sample of CeCoIn5 down to 50mK above absolute zero and applied a magnetic field nearly high enough to entirely suppress superconductivity. They found that the core of the vortices feature electronic spins that are partly aligned with the magnetic field.
This is the first experimental evidence that a theory that describes the properties of superconducting vortices and, for which Abrikosov and Ginzburg received the Nobel Prize in 2003, which does not generally apply in magnetically-induced superconductors.
"When subjected to intense magnetic fields, these materials produce a completely new type of magnetic tornado that grows stronger with increasing fields rather than weakening," said Prof. Bianchi. "The beauty of this compound is how we can experiment without breaking it."
Superconductors hold great promise for technological applications that will change how modern civilization can store and transmit energy - arguably some of the most pressing challenges today. Other notable applications include superconducting digital filters for high-speed communications, more efficient and reliable generators and motors, and superconducting device applications in medical magnetic resonance imaging machines.
The first superconductor was discovered nearly a hundred years ago, and in most materials this curious state with no resistance was shown to arise from the interaction of the electrons with the crystal; however, in this new material, superconductivity is thought to arise from magnetic interactions between electrons.
Article from: http://www.sciencedaily.com/releases/2008/01/080111110510.htm
Demo of small-scale Superconductivity
New Form of Matter Discovered, Part Laser, Part Superconductor
Worlds Largest Superconducting Magnet Switches On
Physicists have 'solved' mystery of levitation
Invisibility cloaks are in sight
Demonstration and the mathematics of invisibility cloaking (Video)
Now you see it, now you don't: cloaking device is not just sci-fi
Magnetic energy? Perhaps
The OC's Magnetic Perpetual Motion Machine
Latest News from our Front Page
'Spectre' Is Doomed: Did North Korea Kill James Bond? No, but Political Correctness will
Comment: Below is an interesting article from Forbes on the fate of the Bond franchise. They asks: 'Spectre' Is Doomed: Did North Korea Kill James Bond?
North Korea probably wasn't behind the Sony hack, China also chimed in. Looks more like a False Flag Hack. North Korea is a lot of things, but behind the Sony attack? Probably not. They have ...
NYPD officer slayings: When the Left's False Narratives Have Deadly Consequences
On Saturday afternoon, Black Brooklynite Ismaaiyl Brinsley ambushed two NYPD police officers and shot them both to death while they were sitting in their patrol car. According to early reports, there was “no warning” and “no provocation.” Brinsley simply approached the vehicle and “unloaded” on the two officers sitting inside. Hours before the assassination, he had announced his intent ...
Saudi oil chief: No conspiracy behind oil prices
Nothing to see here or here
Saudi Arabia's oil chief on Sunday dismissed allegations that his kingdom conspired to bring down oil prices in order to harm other countries and told a summit of Arab energy leaders that he was confident the market would stabilize.
The kingdom, which is dependent on oil revenues, is able to weather lower oil prices due to ...
North Korea's internet is having serious problems
North Korea is having serious connectivity issues this morning, North Korea Tech reports. The country has extremely limited web infrastructure to begin with, but reports from Dyn indicate the country's infrastructure has suffered a series of major outages over the past 24 hours. As a result, anyone at a North Korean IP would have found it nearly impossible to connect ...
The Left, The State And (Opportunistically As Always) Big Business
Adapted from Paul Gottfried‘s address to the 2014 H.L. Mencken Club Conference, at a panel focused on “The Left and the State,“ following remarks made by Carl Horowitz of the National Legal and Policy Center and Keith Preston of Attack the System
I’d like to come back to a remark that Carl Horowitz made in Keith Preston described in his remarks, ...
|More News » |