Fluctuation Effects And Order Parameter Symmetry In The Cuprate Superconductors

TL;DR

This paper investigates how phase fluctuations affect the superconducting transition and order parameter symmetry in cuprates, using a lattice model to estimate transition temperature degradation and analyze nodal structures.

Contribution

It introduces a BCS-like lattice model to study phase fluctuations and determines interaction parameters for optimal doping with $S_{xy}$ symmetry in cuprates.

Findings

Phase fluctuations reduce the mean field transition temperature.

Optimal doping parameters correspond to $S_{xy}$ symmetry.

Nodal positions are insensitive to doping levels.

Abstract

Effect of phase fluctuations on superconducting states with anisotropic order parameters is studied in a BCS like lattice model of cuprate superconductors. The degradation of the mean field transition temperature due to phase fluctuations is estimated within a Kosterlitz-Thouless scenario. Values of the interaction parameters for optimal doping, corresponding to a stable superconducting state of $S_{xy}$ symmetry, which fit the nodal structure of the superconducting order parameter in the Bi2212 compound, are obtained. The angular position of the node is found to be insensitive to the dopant concentration.