Geometric pi Josephson junction: Current-phase relations and critical current

TL;DR

This paper introduces a model for pi Josephson junctions with d-wave superconductors, analyzing how geometry and temperature affect their current-phase relations and critical current.

Contribution

It presents a new model for weak links in d-wave superconductors that predicts current-phase relations and critical currents based on geometry and temperature.

Findings

Model accurately predicts current-phase relations.

Critical current depends on geometric parameters.

Model validated against self-consistent solutions.

Abstract

Josephson junctions with an intrinsic phase shift of pi, so-called pi Josephson junctions, can be realized by a weak link of a d-wave superconductor with an appropriate boundary geometry. A model for the pairing potential of an according weak link is introduced which allows for the calculation of the influence of geometric parameters and temperature. From this model, current-phase relations and the critical current of the device are derived. The range of validity of the model is determined by comparison with selfconsistent solutions.