Physicists report novel interaction between superconductivity and magnetism
January 11, 2008An international collaboration of researchers led by Morten Ring Eskildsen, an assistant professor of physics at the University of Notre Dame, has discovered an altogether new way in which superconducting electrons can interact with an applied magnetic field.
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.
In experiments, Eskildsen’s team investigated the material CeCoIn5, which is a so-called heavy-fermion superconductor with a transition temperature of 2.3K (-456 degrees Fahrenheit). The results were obtained by neutron scattering experiments performed at the Swiss Spallation Neutron Source at the Paul Scheer Institute in Switzerland and were carried out in collaboration with researchers from the University of Montreal, ETH Zurich, the University of Birmingham, Los Alamos National Laboratory and Brookhaven National Laboratory.
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.
While the specific material reported by Eskilden and his colleagues is not directly relevant for technological applications due to its very low transition temperature, many of its properties are similar to those of the high temperature superconductors.
The Eskilden team’s experiments are reported in today’s (Jan. 11) edition of the journal Science.
Source: University of Notre Dame
Nov 09, 2009 |
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Physorg, you tease!
Check out:
http://www.physor...386.html
http://www.physor...394.html
For what they're talking about.
Then check out:
http://www.physor...882.html
Tiny electrically charged organized structures packed close together = win. Synchronize the transfer of energy between them in a wave that just goes around in a circle. There will be certain wavelengths however that generate heat.
See: http://www.physor...936.html
For an example of controlling the direction of light.
Try this on for size: A ring that you take outside, the light from the sun charges it and it magnetizes. Best part is when you take it inside, it stays magnetized and can be used to power electronics via induction coils. Think of the magnet as having four poles that fluctuate between one another... More energy, more poles. That's your current flowing around the super-conductor charged by the light of the sun being captured into a circular wave in the material.
Just as soon as we can reach a true understanding. And this article recaps that. Well done.
http://www.scienc...5860/177
The interesting thing about vortices is that they require an exchange of matter or energy... so when we see vortices in magnetic fields or in star formation, SOMETHING is leaving, and something else is coming in. For these two examples, science cannot yet tell us what this is. Quantum physics will probably be outdated in 50 years. :)