On the Crossover from BCS Superconductivity to Bose Condensation
Abstract
We outline a microscopic approach to the superconducting fluctuations and pairing correlations in the attractive Hubbard model above Tc, using the functional integral method. A crossover from BCS superconductivity to Bose condensation of preformed pairs is studied by constructing the appropriate Ginzburg-Landau functionals. The differences between the lattice and the continuum models are discussed. The case of quasi-two-dimensional superconductors as well as the model with non-local pairing interaction are also examined. The effects of gaussian fluctuations of the order parameter are analyzed in the T-matrix approach, the self-consistent Hartree approach and finally within the Ginzburg-Landau theory. Simlarities with a paramagnon theory of itinerant-electron magnetism are pointed out.
Keywords
Cite
@article{arxiv.cond-mat/0211561,
title = {On the Crossover from BCS Superconductivity to Bose Condensation},
author = {R. Micnas},
journal= {arXiv preprint arXiv:cond-mat/0211561},
year = {2007}
}
Comments
23 pages, 2 figures