Dislocations and the critical endpoint of the melting line of vortex line lattices

TL;DR

This paper presents a theoretical framework for understanding dislocation-driven phase transitions in vortex lattices, explaining the critical endpoint of the melting line observed experimentally at high magnetic fields.

Contribution

It introduces a unified free energy functional approach for dislocation-mediated transitions among vortex phases, including the elastic and amorphous vortex glasses and vortex liquid.

Findings

Explains the origin of the critical endpoint of the melting line.

Provides a unified description of phase transitions in vortex lattices.

Aligns theoretical predictions with recent experimental observations.

Abstract

We develop a theory for dislocation-mediated structural transitions in the vortex lattice which allows for a unified description of phase transitions between the three phases, the elastic vortex glass, the amorphous vortex glass, and the vortex liquid, in terms of a free energy functional for the dislocation density. The origin of a critical endpoint of the melting line at high magnetic fields, which has been recently observed experimentally, is explained.