Positional Disorder (Random Gaussian Phase Shifts) in the Fully Frustrated Josephson Junction Array (2D XY Model)

TL;DR

This paper investigates how positional disorder affects a fully frustrated Josephson junction array, demonstrating that even minimal disorder disrupts the vortex lattice in the thermodynamic limit through analytical and numerical methods.

Contribution

It provides the first evidence that any amount of positional disorder destroys the vortex lattice in the fully frustrated 2D XY model.

Findings

Ground state vortex lattice becomes disordered with any positional disorder

Analytical and numerical evidence supports lattice destruction

Disorder persists in the thermodynamic limit

Abstract

We consider the effect of positional disorder on a Josephson junction array with an applied magnetic field of f=1/2 flux quantum per unit cell. This is equivalent to the problem of random Gaussian phase shifts in the fully frustrated 2D XY model. Using simple analytical arguments and numerical simulations, we present evidence that the ground state vortex lattice of the pure model becomes disordered, in the thermodynamic limit, by any amount of positional disorder.