Disorder driven destruction of a phase transition in a superconductor

TL;DR

This paper studies how increasing disorder in a layered superconductor suppresses its first-order phase transition, transforming it into a crossover without a sharp transition, yet still observable in electrical measurements.

Contribution

It demonstrates how disorder destroys the first-order phase transition in a superconductor, replacing it with a crossover, and identifies the persistence of this crossover in IV characteristics.

Findings

Sharp specific heat peak disappears with disorder

First-order transition replaced by crossover

Crossover detectable in IV measurements

Abstract

We investigate the effects of disorder on a layered superconductor. The clean system is known to have a first order phase transition which is clearly identified by a sharp peak in the specific heat. The peak is lost abruptly as the strength of the disorder is increased. Hence, for strong disorder there is no phase transition as a function of temperature but merely a crossover which is still detectable in the IV characteristic.