A BCS-bose-einstein crossover theory and its application to the cuprates

摘要

We use a "pairing fluctuation" approach to address the behavior of T_c and pseudogap in d-wave superconductors. This theory yields a BCS-Bose-Einstein crossover description of the superconducting transition, which reduces to BCS in the weak coupling (small g) limite and to a Bose-Einstein describtionat large g. We investigate the effects of quasi-two dimensionality, lattice bandstructure and d-wave symmetry, and obtain a cuprate phase diagram, in quantitative agreement with experiment.