Coexistence of Spin-Triplet Superconductivity with Antiferromagnetism in Orbitally Degenerate System: Hartree-Fock Approximation |
| M. Zegrodnika and J. Spałeka,b
aAGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. Mickiewicza 30, 30-059 Kraków, Poland bMarian Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Kraków, Poland |
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| We consider the coexistence of the Hund's-rule-exchange induced spin-triplet paired state with the antiferromagnetic ordering by starting from the extended Hubbard model for a doubly degenerate band. We use the density of states appropriate for the square lattice and treat the problem in the Hartree-Fock approximation. The temperature dependences of the superconducting gaps, the magnetic moment, and the chemical potential are presented. The free energy in the considered phase is evaluated, as well as the corresponding free energies in four additional phases: paramagnetic, ferromagnetic, superconducting of type A and superconducting of type A1 coexisting with ferromagnetism; They occur in the proper range of parameters: band filling n and the interaction parameters U/W and J/W. The low temperature values of the superconducting gaps and staggered magnetic moment are also analyzed as a function of band filling. |
| DOI: 10.12693/APhysPolA.121.801 PACS numbers: 74.20.-z, 74.25.Dw, 75.10.Lp |