The observation of a large Nernst signal eN in an extended region above the critical temperature Tc in hole-doped cuprates provides evidence that vortex excitations survive above Tc. The results support the scenario that superfluidity vanishes because long-range phase coherence is destroyed by thermally-created vortices (in zero field), and that the pair condensate extends high into the pseudogap state in the underdoped (UD) regime. We present a series of measurements to high fields H which provide strong evidence for this phase-disordering scenario.
@article{arxiv.cond-mat/0510470,
title = {The Nernst effect in high-$T_c$ superconductors},
author = {Yayu Wang and Lu Li and N. P. Ong},
journal= {arXiv preprint arXiv:cond-mat/0510470},
year = {2009}
}