Talk:Cooper pair

message: This page appears to be copied completely from http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/coop.html. According to the Copyright info on this page it's not allowed to just be copied, but the author seems open to licencing for educational purposes, which might include Wikipedia. Do we have permission, or does anyone feel like asking? --Apyule 06:54, 3 October 2006 (UTC)
thread_title: Copyright violation

message: How can the electrons be 100 nm apart? Mercury is a metal. It has a lot electrons at the fermi energy.  Arnero 21:40, 4 December 2006 (UTC)
thread_title:  Densitiy of carriers 

message: How is this binding related to Covalent bond or Van der Waals forces ? Arnero 21:40, 4 December 2006 (UTC)
thread_title:  Comparison 

message: What does "The pair are still Cooperic if k1 = k2 and k1 − q = − (k1 − q) = − ( − k2 − q) = − (k2 + q)"
mean? This is the only time that those letters are used - it feels like this is an orphan from a previous edit. Alec.brady 09:42, 7 June 2007 (UTC)
replies: text: I came here to ask about this.  Apparently it has been here for more than two years. 72.75.67.226 (talk) 09:55, 6 October 2009 (UTC)
replies: text: Agreed.  It's gone now.  If anybody puts it back, please add some sort of amplification. Nibios (talk) 20:33, 7 November 2009 (UTC)
thread_title:  Orphan line? 

message: I've removed the article "Cooper electron pair", on the grounds that it's a duplicate of this article and has had a merge tag on it for over a year!  The content of that article was as follows:
:A Cooper (electron) pair is a quasi-bound state of a pair of two electrons in a superconducting material. The composite entity behaves as a particle, with zero spin and charge twice that of an electron. Cooper pairs carry the current in a superconductor. This effect is most known concerning superconductivity.
:A Cooper pair can form in a metal at low temperature. Despite the fact that the electrons Coulomb-repel each other, it may be possible to get an overall attractive force between the two. This is commonly explained in terms of an indirect coupling between the electrons, mediated by the lattice of positive ions.
:Cooper pairs are an integral part of the theory of low-temperature superconductors, BCS theory.
I don't think there's any additional information in this text that isn't already in the Cooper pair article, but others' views would be useful here.  I wonder whether the first sentence or two would make a better (well, simpler for the non-expert reader) introduction to the Cooper pair article than what's currently used. Djr32 (talk) 22:06, 8 November 2008 (UTC)
replies: text: Good job deleting the duplicate article, looks completely redundant to me.  I agree something like the first paragraph (excluding the awkward last sentence) would make a better lead-in for nontechnical readers than what's there now.  Go ahead.  --ChetvornoTALK 00:56, 9 November 2008 (UTC)
thread_title:  Removed article "Cooper electron pair" 

message: If the chemical linkage between copper (and other) conductive atoms were considered to the linkage between an electron between two adjacent atoms, we would have a linked two electron unit which sounds like a Cooper pair. Now if one end of that paired electron system would broken loose due to agitation of the odd Z atoms we would have a loose electron which would be inclined to move in the downstream direction of the field gradient. Then at some point it would be restrained by it's connection to the retained electron link. Then if, by an additional expenditure of energy the retarding link could be broken, we could then imagine a kind of "walking" action of the paired electrons in the downstream direct of the electric gradient. Finally, if we could imagine that both ends of the paired electric linkage system could get loose under low kinetic energy conditions, we could imagine the existence of a loose but linked pair of electrons which could float in the direction of the electric gradient, with no amount of energy input being required for the flow of current process. Can your imagination handle that? We could call it the "Walking electrons concept".WFPM (talk) 05:41, 25 April 2010 (UTC)
thread_title:  "Walking electrons" explanation 

message: What is the spin of a cooper pair, 0 or 1?
As a composite boson, what bosonic properties it does not possess?  —Preceding unsigned comment added by 109.65.8.152 (talk) 04:22, 16 July 2010 (UTC)
thread_title:  Spin and bosonic properties 

message: The two sentences in Bold in the following paragraph are false :
Cooper originally just considered the case of an isolated pair forming in a metal. When one considers the more realistic state consisting of many electrons forming pairs as is done in the full BCS Theory one finds that the pairing opens a gap in the continuous spectrum of allowed energy states of the electrons, meaning that all excitations of the system must possess some minimum amount of energy. This gap to excitations leads to superconductivity, since small excitations such as scattering of electrons are forbidden.[6] The gap appears due to many-body effects between electrons feeling the attraction.
i) The gap to excitations is not itself responsible for superconductivity : for example, a hard-gap in the Density-Of-states simply reflects the absence of quasi-particle excitations in a certain energy range and leads to a (very strong) insulating behavior.
ii) The second sentance is even more false : the gap reflects the attraction between two electrons that form a pair. This naturally leads to a gap in the ONE-particle density-of-states. This is a two-body effect and not a many body effect. What reflects the many-body effect are the coherence peaks at the gap edges. These peaks highlight the difference between a simple gap (no single particle excitations below a certain energy) and the superconducting gap with long-range coherence, which is indeed a many-body effect.
In order to create a magnetic field, wouldn't it be necessary for the conducting electrons to find a "tunnel" within the unit cell through which they could float (2 at a time?) without resistance? So wouldn't the unit cell structure have to be consistent with such a path?WFPM (talk) 22:53, 4 May 2011 (UTC)
thread_title:  Relation with superconductivity 

message: * 
X1\ (talk) 01:04, 19 November 2019 (UTC)
thread_title:  useful addition, regarding new [[State of matter|states of matter]] ? 

message: Should there be some discussion of tunneling of pairs?  Actually, I got interested in the question from alpha decay, in which bound states of protons and neutrons tunnel out of a nucleus. How is it that they manage to tunnel together?  Pretty much the same way that Cooper pairs do. Gah4 (talk) 00:32, 2 October 2020 (UTC)
thread_title:  tunneling