Correlation Lengths in the Vortex Line Liquid of a High Tc Superconductor

TL;DR

This study uses a 3D XY model to measure and analyze the longitudinal correlation length in the vortex line liquid phase of high-temperature superconductors, revealing how it scales near the vortex lattice melting transition.

Contribution

It provides the first explicit measurement of the longitudinal correlation length in the vortex liquid phase of high Tc superconductors using a realistic model.

Findings

Correlation length scales with magnetic field and anisotropy.

Longitudinal correlations extend significantly above the vortex lattice melting point.

Results help understand vortex behavior in YBCO near melting.

Abstract

We use the three dimensional uniformly frustrated XY model, as a model for a high temperature superconductor in an applied magnetic field, to explicitly measure the longitudinal correlation length xi_z in the vortex line liquid phase. We determine the scaling of xi_z with magnetic field and system anisotropy close to the vortex lattice melting transition. We apply our results to determine the extent of longitudinal correlations in YBCO just above melting.