Temperature Dependence Of Cuprate Superconductors' Order Parameter

TL;DR

This paper models the temperature dependence of the order parameter in underdoped cuprate superconductors using a charged boson framework, revealing a characteristic trapezoidal shape influenced by phase fluctuations and interlayer coupling.

Contribution

It introduces a theoretical model that quantitatively describes the order parameter's temperature dependence in cuprates, aligning with experimental superfluid density and ARPES data.

Findings

Order parameter declines slowly at low T due to phase fluctuations.

Rapid fall of order parameter above BKT temperature.

Model matches experimental superfluid density and ARPES measurements.

Abstract

A model of charged hole-pair bosons, with long range Coulomb interactions and very weak interlayer coupling, is used to calculate the order parameter -Phi- of underdoped cuprates. Model parameters are extracted from experimental superfluid densities and plasma frequencies. The temperature dependence -Phi(T)- is characterized by a 'trapezoidal' shape. At low temperatures, it declines slowly due to harmonic phase fluctuations which are suppressed by anisotropic plasma gaps. Above the single layer Berezinski-Kosterlitz-Thouless (BKT) temperature, Phi(T) falls rapidly toward the three dimensional transition temperature. The theoretical curves are compared to c-axis superfluid density data by H. Kitano et al., (J. Low Temp. Phys. 117, 1241 (1999)) and to the -transverse nodal velocity- measured by angular resolved photoemmission spectra on BSCCO samples by W.S. Lee et al., (Nature 450, 81 (2007)), and by A. Kanigel, et al., (Phys. Rev. Lett. 99, 157001 (2007)).