Phase Fluctuations and BCS-LP Crossover in 2D Short Coherence Length Superconductors |
| B. Tobijaszewska and R. Micnas Institute of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland |
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| We study the effects of phase fluctuations in 2D short-coherence length superconductors on the basis of the extended Hubbard model with intersite attraction. In the Kosterlitz-Thouless scenario the critical temperatures for anisotropic pairings were determined and compared with the ones from BCS Hartree-Fock approximation. The Uemura-type plots, i.e. the critical temperature vs. zero temperature phase stiffness, were obtained for extended s-wave and dx2-y2-wave pairings. We also discuss the crossover from BCS to local pair superconductivity for d-wave pairing. |
| DOI: 10.12693/APhysPolA.97.393 PACS numbers: 74.20.-z, 71.10.Fd, 74.20.Fg, 74.20.Mn, 74.72.-h |