Participation-Ratio Entropy and Critical Fluctuations in the Thermodynamics of Pancake Vortices

TL;DR

This paper investigates the thermodynamics of two-dimensional type-II superconductors near the phase transition, using participation-ratio entropy to analyze critical fluctuations and phase transition nature.

Contribution

It introduces the use of participation-ratio entropy to fully describe the thermodynamics of pancake vortices in superconductors, combining analytical and numerical methods.

Findings

Identification of a weak first-order phase transition.

Analytical results for participation-ratio entropy.

Monte Carlo simulation confirming theoretical predictions.

Abstract

We report on a study of the thermodynamics of the Ginzburg-Landau model for two-dimensional type-II superconductors near the transition from the normal state to the Abrikosov-lattice state. We couch our analysis in terms of the participation-ratio entropy, $s(P)$, which expresses the volume in order-parameter-space with a given participation-ratio for the local superfluid density. $s(P)$ completely determines the thermodynamics of the system. We report on results for $s(P)$ obtained analytically using perturbation expansion methods and numerically using Monte Carlo simulation methods and discuss the weak first-order phase transition which occurs in this system in terms of the properties of $s(P)$.