Asymmetric magnetic interference patterns in 0-pi Josephson junctions

TL;DR

This paper investigates the asymmetric magnetic interference patterns in 0-pi Josephson junctions, revealing how self-fields cause asymmetries in critical current, explaining experimental observations in YBCO-Pb junctions with twin boundaries.

Contribution

It demonstrates that self-fields induce asymmetries in 0-pi Josephson junctions, providing a theoretical explanation for previously unexplained experimental features.

Findings

Self-fields cause asymmetry in critical current under magnetic field reversal.

Numerical models align with experimental data from YBCO-Pb junctions.

Asymmetries explain features observed in single twin boundary junctions.

Abstract

We examine the magnetic interference patterns of Josephson junctions with a region of 0- and of pi-phase shift. Such junctions have recently been realized as c-axis YBCO-Pb junctions with a single twin boundary in YBCO. We show that in general the junction generates self-fields which introduces an asymmetry in the critical current under reversal of the magnetic field. Numerical calculations of these asymmetries indicate they account well for the unexplained features observed in single twin boundary junctions.