Nonsinusoidal current-phase relation in strongly ferromagnetic and moderately disordered SFS junctions

TL;DR

This paper investigates the Josephson current in superconductor-ferromagnet-superconductor (SFS) junctions with strong ferromagnetism and disorder, revealing nonsinusoidal current-phase relations and temperature-induced 0-transitions.

Contribution

It provides a detailed analysis of the current-phase relation in strongly ferromagnetic, disordered SFS junctions, including the effects of ballistic and diffusive regimes.

Findings

Nonsinusoidal current-phase relation observed.

Temperature-induced 0-transitions demonstrated.

Critical current dependence on temperature studied.

Abstract

We study the Josephson current in a junction comprising two superconductors linked by a strong ferromagnet in presence of impurities. We focus on a regime where the electron (and hole) motion is ballistic over the exchange length and diffusive on the scale of the weak link length. The current-phase relation is obtained for both two- and three dimensional ferromagnetic weak links. In the clean limit, the possibility of temperature-induced 0- transitions is demonstrated while the corresponding critical current versus temperature dependences are also studied.