Superharmonic long-range triplet current in a diffusive Josephson junction

TL;DR

This paper investigates the Josephson current in a diffusive ferromagnetic bilayer, revealing that non-collinear magnetizations lead to a dominant second harmonic in the current-phase relation, indicating long-range triplet pairing.

Contribution

It demonstrates the dominance of the second harmonic in the current-phase relation due to long-range triplet pairs in a diffusive Josephson junction with non-collinear magnetizations.

Findings

Second harmonic dominates the current-phase relation.

Long-range triplet pairs enable coherent electron propagation.

Magnetization orientation critically affects the Josephson current.

Abstract

We study the Josephson current through a long ferromagnetic bilayer in the diffusive regime. For non-collinear magnetizations, we find that the current-phase relation is dominated by its second harmonic, which corresponds to the long-range coherent propagation of two triplet pairs of electrons.