Interference patterns of multifacet 20x(0-pi-) Josephson junctions with ferromagnetic barrier

TL;DR

This paper investigates the interference patterns in multifacet Josephson junctions with ferromagnetic barriers, revealing how non-uniform flux density caused by screening currents affects their critical current behavior.

Contribution

It introduces a method to realize multifacet Josephson junctions with alternating critical current density and analyzes the impact of flux inhomogeneity on their properties.

Findings

Anomalous critical current features are linked to non-uniform flux density.

Screening currents induce flux variations affecting junction behavior.

The study provides insights into flux effects in ferromagnetic Josephson junctions.

Abstract

We have realized multifacet Josephson junctions with periodically alternating critical current density (MJJs) using superconductor-insulator-ferromagnet-superconductor heterostructures. We show that anomalous features of critical current vs. applied magnetic field, observed also for other types of MJJs, are caused by a non-uniform flux density (parallel to the barrier) resulting from screening currents in the electrodes in the presence of a (parasitic) off-plane field component.