BKT universality class in the presence of correlated disorder

TL;DR

This paper investigates how spatially correlated disorder affects the Berezinskii-Kosterlitz-Thouless (BKT) transition in quasi-two-dimensional superconductors, focusing on whether it alters the BKT universality class and explaining experimental observations.

Contribution

It provides a detailed analysis of the impact of correlated disorder on the BKT transition, clarifying its role in the universality class and experimental signatures.

Findings

Correlated disorder influences the superfluid-density jump.

The BKT universality class remains unchanged despite correlated disorder.

Disorder causes smearing of the BKT transition signatures.

Abstract

The correct detection of the Berezinskii-Kosterlitz-Thouless (BKT) transition in quasi-two-dimensional superconductors still remains a controversial issue. Its main signatures, indeed, are often at odds with the theoretical expectations. In a recent work\cite{me} we have shown that the presence of spatially correlated disorder plays a key role in this sense being it the reason underlying the experimentally-observed smearing of the universal superfluid-density jump. In the present paper, we closely investigate the effects of correlated disorder on the BKT transition, addressing specifically the issue whether it changes or not the BKT universality class.