Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Non s-wave superconductivity

  1. Dec 4, 2005 #1
    In BCS you make the assumption that the effective electron-electron interaction is constant within a small shell around the fermi surface and zero otherwise. From this you get a constant spherical gap.

    In non s-wave SC there is a specific form for the gap ie, [tex]\Delta_0 = [ \cos (k_x a) - \cos (k_y a)] [/tex]. I know that you can calculate the gap parameter using group theory and the underlying symmetry of the crystal lattice. But is there a way to choose an arbitary form for [tex] k \cdot k^\prime[/tex], self consistently solve the gap equation and arrive at a d-wave gap or any other non s-wave gap?

    How do you choose the effective electron-electron interaction? Is it based on the atomic orbitals that are believed to be responsible for SC? I've done a few searches and all I find is a assumption for the form of the gap. Thanks
    Last edited: Dec 4, 2005
  2. jcsd
  3. Dec 4, 2005 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2018 Award

    This isn't an easy question to answer because this is still something being worked on. Something like the t-J method using mean-field approximation can drop the d-wave symmetry onto your lap (this assertion is still controversial). In many instances, the symmetry is inserted by hand because that is the product of experimental observation. There's a persuasive reason why this is having that d-wave symmetry - the valence shell of the Cu in the CuO plane where superconductivity is thought to reside. The transition metals have d-orbitals valence shell.

    Note that for the Ruthenates, you have a p-wave symmetry for the pair.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook