Phenomenological correlations in high-temperature superconductors

TL;DR

This paper interprets the quadratic parameter in Ginzburg-Landau theory for high-temperature superconductors, linking the energy gap at the Fermi surface to a strong correlation between critical magnetic field and temperature.

Contribution

It provides a novel interpretation of the Ginzburg-Landau quadratic parameter, connecting microscopic energy gaps to macroscopic critical field and temperature correlations.

Findings

Predicted a strong correlation between zero kelvin upper critical field and critical temperature.

Observed the predicted correlation in high-temperature superconductor data.

Linked the energy gap at the Fermi surface to the effective potential in superconductivity theory.

Abstract

An interpretation of the quadratic parameter of the Ginzburg-Landau theory of superconductivity is presented in this paper. The negative term in the potential, which allows the spontaneous symmetry breaking, is interpreted as a direct contribution from the energy gap at the Fermi surface to the effective potential. As a result, in the London approximation of the Ginzburg-Landau theory for type-II superconductors, a strong correlation is predicted and observed between the upper critical field at zero kelvin and the critical temperature in high temperature superconductors.