https://doi.org/10.1140/epjb/e2004-00007-3
Anisotropic pairing with repulsive interactions in a model with different orbitals per site
Instituto de Ciencia de Materiales de
Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
Corresponding author: a paco.guinea@icmm.csic.es
Received:
6
October
2003
Revised:
1
December
2003
Published online:
30
January
2004
An extension of the Hubbard model, with two orbitals of different symmetry per site is studied. When the two orbitals are hybridized by crystal field effects, the BCS approximation shows that the model has an instability towards anisotropic superconductivity. The competition between superconductivity and antiferromagnetism, and the relevance of other pairing mechanisms, like the Kohn-Luttinger instability, are also analyzed.
PACS: 71.10.Fd – Lattice fermion models (Hubbard model, etc.) / 74.20.Mn – Nonconventional mechanisms
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003