844 research outputs found
Fluctuating order parameter in doped cuprate superconductors
We discuss static fluctuations of the d-wave superconducting order parameter
in CuO planes, due to quasiparticle scattering by charged dopants.
The analysis of two-particle anomalous Green functions at permits to
estimate the mean-square fluctuation ,
averaged in random dopant configurations, to the lowest order in doping level
. Since is found to saturate with growing doping level while
remains to grow, this can explain the collapse of at overdoping.
Also we consider the spatial correlations for
order parameter in different points of the plane.Comment: RevTex4, 3 pages, to be published in Proceedings of New3SC-4
International Conference, San Diego, California, January 15-21, 200
Superconductivity and superconducting order parameter phase fluctuations in a weakly doped antiferromagnet
The superconducting properties of a recently proposed phenomenological model
for a weakly doped antiferromagnet are analyzed, taking into account
fluctuations of the phase of the order parameter. In this model, we assume that
the doped charge carriers can't move out of the antiferromagnetic sublattice
they were introduced. This case corresponds to the free carrier spectra with
the maximum at , as it was observed in ARPES
experiments in some of the cuprates in the insulating state [1]. The doping
dependence of the superconducting gap and the temperature-carrier density phase
diagram of the model are studied in the case of the pairing
symmetry and different values of the effective coupling. A possible relevance
of the results to the experiments on high-temperature superconductors is
discussed.Comment: 16 pages, 4 figure
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