Magnetic interference patterns in superconducting junctions: Effects of anharmonic current-phase relations

TL;DR

This paper develops a microscopic theory for magnetic-field modulation of critical currents in Josephson junctions with anharmonic current-phase relations, revealing temperature-dependent deviations from conventional interference patterns.

Contribution

It introduces a detailed microscopic model accounting for anharmonic effects and transparency distributions, enhancing understanding of magnetic interference in complex Josephson junctions.

Findings

Deviations depend on transparency distribution and temperature.

Deviations vanish near Tc and at T=0 for constant transparency.

Maximum deviation occurs at T=0 with Dorokhov bimodal distribution.

Abstract

A microscopic theory of the magnetic-field modulation of critical currents is developed for plane Josephson junctions with anharmonic current-phase relations. The results obtained allow examining temperature-dependent deviations of the modulation from the conventional interference pattern. For tunneling through localized states in symmetric short junctions with a pronounced anharmonic behavior, the deviations are obtained and shown to depend on distribution of channel transparencies. For constant transparency the deviations vanish not only near Tc, but also at T=0. If Dorokhov bimodal distribution for transparency eigenvalues holds, the averaged deviation increases with decreasing temperature and takes its maximum at T=0.