Josephson effect between triplet superconductors through a ferromagnetic barrier of finite width

TL;DR

This paper investigates how a finite-width ferromagnetic barrier affects charge and spin transport, Josephson currents, and 0- transitions in a junction between triplet superconductors, using Green's functions derived from Bogoliubov-de Gennes wavefunctions.

Contribution

It introduces a detailed analysis of finite barrier width effects on Josephson and spin currents, challenging the common -function approximation in such systems.

Findings

Finite barrier width influences 0- transitions.

Finite width affects spin current behavior.

The -function approximation may be inadequate for finite barriers.

Abstract

Charge and spin transport in a junction involving two triplet superconductors and a ferromagnetic barrier are studied. We use Bogoliubov-de Gennes wavefunctions to construct the Green's function, from which we obtain the Josephson currents in terms of the Andreev reflection coefficients. We focus on the consequences of a finite barrier width for the occurrence of 0-\pi transitions and for the spin currents, and examine the appropriateness of the common \delta-function approximation for the tunneling region.