Europhys. Lett, 48 (4), pp. 449-454 (1999)
Exotic ground states and impurities in multiband superconductors
D. F. Agterberg 1, V. Barzykin 1and L. P. Gor'kov 1,2
1 National High Magnetic Field Laboratory,
Florida State University
1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, USA
2 L. D. Landau Institute for Theoretical Physics - Chernogolovka, 142432, Russia
(received 28 July 1999; accepted 9 September 1999)
PACS. 74.20De - Phenomenological theories (two-fluid, Ginzburg-Landau, etc.).
PACS. 74.25Dw - Superconductivity phase diagrams.
We consider the effect of isotropic impurity scattering on the exotic superconducting states that arise from the usual BCS mechanism in substances of cubic and hexagonal symmetry where the Fermi surface contains inequivalent but degenerate pockets (e.g. around several points of high symmetry). As examples we look at CeCo2, CeRu2, and LaB6; all of which have such Fermi surface topologies and the former exhibits unconventional superconducting behavior. We find that while these non s-wave states are suppressed by non-magnetic impurities, the suppression is much weaker than would be expected for unconventional superconductors with isotropic non-magnetic impurity scattering.
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