Affiliation:
1. National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, USA
Abstract
We consider the pairing state due to the usual Bardeen-Cooper-Schrieffer mechanism in substances where the Fermi surface forms pockets around several points of high symmetry. The symmetry imposed on the multiple pocket positions can give rise to a multidimensional nontrivial superconducting order parameter. A complicated mechanism is not required for unusual superconductivity to exist, just the usual phonon attraction and Coulomb repulsion. Time reversal symmetry is broken, so the superconducting state also has orbital magnetism. In some sense, these superconductors are similar to superfluid3 He, which is known to have an 18-dimensional order parameter and a complicated phase diagram. We suggest several candidate substances where ordering of this kind may appear and discuss how these phases may be identified. Superconductivity in these new materials is expected to be much less sensitive to impurities than in other non s-wave superconductors.1
Publisher
World Scientific Pub Co Pte Lt
Subject
Condensed Matter Physics,Statistical and Nonlinear Physics