Superfluid density near the critical temperature in the presence of random planar defects

TL;DR

This paper investigates how randomly distributed planar defects affect the superfluid density near the critical temperature in superconductors, using a modified Ginzburg-Landau model and comparing results with experimental data.

Contribution

It introduces a theoretical framework to quantify the impact of planar defects on superfluid density near Tc, incorporating disorder effects into the Ginzburg-Landau theory.

Findings

Derived the correction to superfluid density due to planar defects.

Found qualitative agreement with experimental measurements in YBCO crystals.

Provided a model for disorder effects in high-temperature superconductors.

Abstract

The superfluid density near the superconducting transition is investigated in the presence of spatial inhomogeneity in the critical temperature. Disorder is accounted for by means of a random $T_c$ term in the conventional Ginzburg-Landau action for the superconducting order parameter. Focusing on the case where a low-density of randomly distributed planar defects are responsible for the variation of $T_c$, we derive the lowest order correction to the superfluid density in powers of the defect concentration. The correction is calculated assuming a broad Gaussian distribution for the strengths of the defect potentials. Our results are in a qualitative agreement with the superfluid density measurements in the underdoped regime of high-quality YBCO crystals by Broun and co-workers.