"Fragile superconductivity": a kinetic glass transition in the vortex matter of the high-temperature superconductor YBa2Cu3O7-d

TL;DR

This paper investigates the glassy behavior of vortex matter in the high-temperature superconductor YBa2Cu3Ox, exploring its kinetic glass transition and comparing it to other glassy states like spin and structural glasses.

Contribution

It provides a microscopic analysis of the fragile vortex glass transition in YBa2Cu3Ox, linking it to broader glassy phenomena and the concept of kinetic versus thermodynamic transitions.

Findings

Identification of a fragile kinetic glass transition in vortex matter

Comparison of vortex glass behavior with structural and spin glasses

Insights into the complex relaxation dynamics of vortex states

Abstract

Of the many different kinds of glassy states found in nature, spin glasses and structural glasses (e.g. normal window glass) have probably received the most attention. One of the central questions concerning the glassy state is whether the "glass" is a distinct thermodynamic phase from the "liquid" phase. It is believed that this may actually be the case for spin glasses, whereas the glass transition in structural glasses appears to be mostly kinetic in nature. Supercooled structural liquids, however, exhibit a wide range of behaviors, which can be classified using the "strong-fragile" scheme of Angell, where the terms "strong" and "fragile" refer to Arrhenius and highly non-Arrhenius relaxation behaviors, respectively. For the extremely fragile liquids, a thermodynamic origin of the glass transition cannot be ruled out. A microscopic understanding of the complexity leading to different degrees of fragility and affecting the kinetic glass transition is, however, lacking. Also the connection, if any, between the different kind of glass states (spin, structural, etc.) is unclear. Here we examine the glassy behavior of a novel type of matter, namely the vortex matter in the high-temperature superconductor (HTSC) YBa2Cu3Ox.