Superconductivity of the Two-Dimensional Penson--Kolb Model |
| W.R. Czart and S. Robaszkiewicz Institute of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań |
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| Received: July 2, 2001 |
| Two-dimensional (d=2) Penson--Kolb model, i.e. the tight-binding model with the pair-hopping (intersite charge exchange) interaction, is considered and the effects of phase fluctuations on the s-wave superconductivity of this system are discussed within the Kosterlitz--Thouless scenario. The London penetration depth λ at T= 0, the Kosterlitz-Thouless critical temperature Tc, and the Hartree--Fock approximation critical temperature Tp are determined as a function of particle concentration and interaction. The Uemura type plots (Tc vs. λ-2(0)) are derived. Beyond weak coupling and for low concentrations they show the existence of universal scaling: Tc~1/λ2(0), as it was previously found for the attractive Hubbard model and for the models with intersite electron pairing. |
| DOI: 10.12693/APhysPolA.100.885 PACS numbers: 74.20.--z, 71.28.+d, 74.25.Ha |