0-$\pi$ transition in magnetic triplet superconductor Josephson junctions

TL;DR

This paper investigates the 0-$$ transition in Josephson junctions with equal-spin-pairing triplet superconductors and ferromagnetic barriers, revealing how barrier interactions can reverse current sign and generate spin currents.

Contribution

It introduces a perturbative analysis of triplet superconductor Josephson junctions with ferromagnetic barriers, supported by non-perturbative numerical verification.

Findings

Barrier moment interaction can reverse Josephson current sign.

A phase-independent spin current arises from reflection processes.

Analytic predictions are confirmed by Bogoliubov-de Gennes calculations.

Abstract

We examine a Josephson junction involving two arbitrary equal-spin-pairing unitary triplet superconductors and a ferromagnetic tunneling barrier. Using perturbation theory, we show how the interaction of the barrier moment with the spin of the tunneling triplet Cooper pairs can reverse the sign of the Josephson charge current. This also results in a Josephson spin current, which contains a phase-independent contribution due to reflection processes at the barrier. We verify our analytic predictions using a non-perturbative Bogoliubov-de Gennes method.