Weak point disorder in strongly fluctuating flux-line liquids

TL;DR

This paper investigates how weak point defects affect the properties of a highly fluctuating flux-line liquid using a hydrodynamic model mapped onto a relativistic boson system, revealing disorder-induced modifications to correlation functions and elastic properties.

Contribution

It introduces a hydrodynamic framework for flux-line liquids with quenched disorder, extending previous models to include arbitrary flux line curvature and loop formation, and calculates disorder effects on key physical quantities.

Findings

Scalar disorder enhances loop nucleation.

Polar defects decrease the tilt modulus.

Disorder modifies correlation functions and elastic moduli.

Abstract

We consider the effect of weak uncorrelated quenched disorder (point defects) on a strongly fluctuating flux-line liquid. We use a hydrodynamic model which is based on mapping the flux-line system onto a quantum liquid of relativistic charged bosons in 2+1 dimensions [P. Benetatos and M. C. Marchetti, Phys. Rev. B 64, 054518, (2001)]. In this model, flux lines are allowed to be arbitrarily curved and can even form closed loops. Point defects can be scalar or polar. In the latter case, the direction of their dipole moments can be random or correlated. Within the Gaussian approximation of our hydrodynamic model, we calculate disorder-induced corrections to the correlation functions of the flux-line fields and the elastic moduli of the flux-line liquid. We find that scalar disorder enhances loop nucleation, and polar (magnetic) defects decrease the tilt modulus.