Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Ylide on 11/09/2004 03:35:28
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So I was reading this month's Scientific American and saw that the first Fermi condensates have been made using K-40 atoms at a startlingly low 0.5x10^-9 K temperature.
In the article, it's mentioned that this breakthrough will help advance high-temperature (ie room temp) superconductors. My understanding of quantum physics stops after the 2nd semester of physical chemistry, so I don't really understand the connection between the two. Making a condensate out of fermions at near-absolute-zero temperatures doesn't seem like it has much to do with superconductors. I would venture a guess that having a material with all its atoms in the same quantum state has something to do with it, but Bose-Einstein and Fermi condensates only exist (so far) at super low temps. What am I missing here?
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I think the significance is that the theoretical understanding of superconductors, and especially high temperature superconductors, is so poor that any experiment that produces the correct result advances the basic knowledge we need to make products out of this scientific curiosity.
It is a good step to produce quantum-state condensates of elements other than helium. Super-fluid helium is the prototype for all the other Bose and Fermi condensates. It has been known to exist for many years, but our understanding of these special phases of matter is limited.
It has been pointed out that since the universe is too hot to allow Bose and Fermi condensates to exist in nature, that the laboratory was the first place these phases of matter ever existed. (Barring extra-terrestrial science.)
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So it's really just to give an understanding of how condensates behave and then extrapolate that to superconductor behavior? Why are Fermi condensates, as the article suggests, so much more important for this understanding? Are most potentially superconducting elements made up of fermions?
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Well, electrons are fermions, as are any particles or atoms which have half-integral spin in units of h/2pi. Bosons have integral spin. Of course that makes Cooper pairs bosons. I think fermions and bosons are both very important for superconducting research, since materials are both. Right now it appears that superconduction is limited to bosons, since that is when all the particles may go into the same state. In the case of electrons in metals, they form Cooper pairs and become bosons.
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I believe the Fermi condensates involved fermion spin pairing of some sort that made it behave like a BEC. I understand this a little better...thanks.
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