Vorticity, phase stiffness and the cuprate phase diagram

We review results obtained from vortex-Nernst experiments in cuprates. Evidence for a loss of phase coherence at the Meissner transition T-c0 is derived from vortex-like excitations that persist to high temperature T. Below T-c0, the Nerstat signal provides a determination of the upper critical field H-c2 vs. doping x. Implications for the cuprate phase diagram are discussed. (C) 2004 Elsevier B.V. All rights reserved.