Flux-lattice melting in LaO$_{1-x}$F$_{x}$FeAs: first-principles prediction

TL;DR

This paper theoretically predicts the flux-lattice melting behavior in specific iron-based superconductors using first-principles calculations and the Hansen-Verlet criterion, providing insights into vortex dynamics.

Contribution

It introduces a novel first-principles approach to predict flux-lattice melting lines in iron-based superconductors combining density functional theory and the mean-field substrate method.

Findings

Flux-lattice melting lines are predicted for LaO$_{1-x}$F$_x$FeAs.

Hansen-Verlet criterion is validated for vortex-liquid freezing.

First-principles calculations effectively model vortex behavior.

Abstract

We report the theoretical study of the flux-lattice melting in the novel iron-based superconductor $LaO_{0.9}F_{0.1}FeAs$ and $LaO_{0.925}F_{0.075}FeAs$. Using the Hypernetted-Chain closure and an efficient algorithm, we calculate the two-dimensional one-component plasma pair distribution functions, static structure factors and direct correlation functions at various temperatures. The Hansen-Verlet freezing criterion is shown to be valid for vortex-liquid freezing in type-II superconductors. Flux-lattice meting lines for $LaO_{0.9}F_{0.1}FeAs$ and $LaO_{0.925}F_{0.075}FeAs$ are predicted through the combination of the density functional theory and the mean-field substrate approach.