Diode effect in the Fraunhofer pattern of disordered planar Josephson junctions

TL;DR

This paper investigates how disorder and imperfections influence the Josephson diode effect in planar junctions, revealing that mirror symmetry suppresses the effect and that it is enhanced at Fraunhofer pattern nodal points.

Contribution

It provides a comprehensive analysis of how spatial inhomogeneity and disorder affect the Josephson diode effect in planar junctions, including multi-terminal and parallel systems.

Findings

Mirror symmetry at zero-field suppresses the diode effect.

Disorder amplifies the diode effect at Fraunhofer pattern nodal points.

The study extends to multi-terminal and parallel Josephson junction systems.

Abstract

The Josephson diode effect describes the property of a Josephson junction to have different values of the critical current for different direction of applied bias current and it is the focus of intense research thanks to the possible applications. The ubiquity of the effect experimentally reported calls for a study of the impact that disorder can have in the appearance of the effect. We study the Fraunhofer pattern of planar Josephson junctions in presence of different kinds of disorder and imperfections and we find that a junction that is {\it mirror} symmetric at zero-field forbids the diode effect and that the diode effect is typically magnified at the nodal points of the Fraunhofer pattern. The work presents a comprehensive treatment of the role of pure spatial inhomogeneity in the emergence of a diode effect in planar junctions, with an extension to the multi-terminal case and to systems of Josephson junctions connected in parallel.