Suppression of the vortex glass transition due to correlated defects with a persistent direction perpendicular to an applied magnetic field

TL;DR

This paper theoretically demonstrates that correlated defects perpendicular to an applied magnetic field suppress the vortex-glass transition in type II superconductors, explaining anomalous resistive broadening observed in experiments.

Contribution

It introduces a theoretical framework showing how perpendicular correlated defects depress the vortex-glass transition, extending understanding of vortex behavior in disordered superconductors.

Findings

Correlated defects perpendicular to the magnetic field suppress the vortex-glass transition.

The theory explains resistive broadening in YBCO with columnar defects.

Other phenomena related to correlated defects are discussed.

Abstract

It is found on the basis of the lowest Landau level approach for the Ginzburg-Landau model that, in bulk type II superconductors with strong line disorder directed {\it perpendicularly} to an applied field, the continuous vortex-glass transition is depressed to the low $T$ limit in the limit of weak {\it point} disorder. An anomalous resistive broadening in twin-free YBCO with columnar defects in a field parallel to the layers is discussed based on this theoretical finding. Other phenomena which, we argue, arise indirectly from this mechanism in type II superconductors including correlated defects are also discussed.