Vortex-pair unbinding in the normal state of two-dimensional short–coherence-length superconductors
Department of Physics, Boston College - Chestnut Hill, MA 02167, USA
Accepted: 3 May 2000
We study the superconducting transition in the attractive Hubbard model in two dimensions using the self-consistent T-matrix approximation. We demonstrate that for large systems, this approximate method produces XY critical scaling in the correlation length and pair susceptibility. Our data also exhibits XY finite-size scaling. For the parameters considered, the critical regime is quite large, extending beyond 5 times . We discuss the role of vortex-pair unbinding in the normal state in the context of pseudogap behaviour and the relevance to the physics of underdoped cuprates.
PACS: 74.25.-q – General properties; correlations between physical properties in normal and superconducting states / 74.20.-z – Theories and models of superconducting state / 74.25.Dw – Superconductivity phase diagrams
© EDP Sciences, 2000