I'd like to know more about cooper pairing. If anyone has any good resources I'd appreciate it if they shared them. Thanks in advance.
I am typically a fan of the Hyperphysics website. It has a wealth of solid info on just about everything and I always recommend people to go there first if they have a question. This, however, is the one exception. The info on Cooper paring is rather vague, and I don't understand this overemphasis on the "band gap"! The existence of the band gap does not automatically imply that these cooper pairs can conduct without resistance. If this were true, than insulators would have the same properties since there's a huge band gap in a typical insulator! In a superconductor, this band gap (more accurately the energy gap in the single-particle band structure) is the energy needed to break apart a cooper pair.Originally posted by suyver
This, and the links therein, is a good place to start.
That is indeed a nice site!Originally posted by ZapperZ
:)Originally posted by suyver
That is indeed a nice site!
I quite like the cartoon for high Tc superconductivity!
A band gap is a gap in the material's energy level. In solids, the energy levels are continuous but only over a certain range. In metals, if you estimate the conduction electrons as "free electrons", then you have a dispersion relation looking likegarytse86 said:what exactly is a band-gap? Is this linked with periodic potential?
Er.. not quite. The gap in the energy spectrum of a superconductor is caused by the energy required to break apart a Cooper Pair.nbo10 said:In a superconductor the band gap is not caused by a periodic potential but is caused by the electron-phonon interaction.
Most of the high-Tc superconductors (the cuprates) are doped with oxygen to add "holes" to the insulating parent compounds. These are the ones with the highest Tc at optimal doping. There is a sister compound of the cuprates that are electron doped. They tend to not have the same high Tc as the hole doped. There are also indications that their physics may be different than the hole doped.Silverious said:Well, haven't superconductors been made at 150K by adding an Oxygen? Seems like I heard that somewhere.
Carefull..... Only a small portion of electrons are invloved in the pairing.kurious said:In type 1 superconductors there are lots of cooper pairs and there is a rapid change in conductivity.Type 2 superconductors show a gradual change from normal to super conductivity .Perhaps type 2 superconductors conduct increasingly better because electron movement through a lattice causes the formation of "groups" of atoms in the lattice which then cause further electron movements in such a way as to increase the formation of yet more groups and so on, as the temperature decreases