Phase fluctuations and BCS-LP crossover in 2D short coherence length superconductors

We study the effects of phase fluctuations in 2D short-coherence length sup erconductors on the basis of the extended Hubbard model with intersite attr action. In the Kosterlitz-Thouless scenario the critical temperatures for a nisotropic pairings were determined and compared with the ones from BCS Har tree-Fock approximation. The Uemura-type plots, i.e. the critical temperatu re vs. zero temperature phase stiffness, were obtained for extended s-wave and d(x2-y2)-wave pairings. We also discuss the crossover from BCS to local pair superconductivity for d-wave pairing.