Edge effects in a frustrated Josephson junction array with modulated couplings

TL;DR

This paper investigates how modulated couplings in a Josephson junction array affect vortex lattice disordering, proposing resistance measurements as a probe and supporting findings with extensive simulations.

Contribution

It introduces a novel analysis of edge effects and resistance behavior in modulated Josephson junction arrays undergoing vortex lattice transitions.

Findings

Resistance scales as R_L(T) ~ A(T)/L with A(T) ∝ (T - T_cI) in certain geometries.

Edge dissipation influences the linear resistance near the vortex transition.

Simulations support the proposed physical mechanisms and transition behaviors.

Abstract

A square array of Josephson junctions with modulated strength in a magnetic field with half a flux quantum per plaquette is studied by analytic arguments and dynamical simulations. The modulation is such that alternate columns of junctions are of different strength to the rest. Previous work has shown that this system undergoes an XY followed by an Ising-like vortex lattice disordering transition at a lower temperature. We argue that resistance measurements are a possible probe of the vortex lattice disordering transition as the linear resistance $R_{L}(T)\sim A(T)/L$ with $ A(T) \propto (T-T_{cI})$ at intermediate temperatures $T_{cXY}>T>T_{cI}$ due to dissipation at the array edges for a particular geometry and vanishes for other geometries. Extensive dynamical simulations are performed which support the qualitative physical arguments.