Determining the current polarization in Al/Co nanostructured point contacts

TL;DR

This paper investigates the spin polarization in Al/Co nanostructured point contacts through Andreev reflection measurements, providing a model that accurately describes conductance behavior and unambiguously determines current polarization.

Contribution

It introduces a model with two spin-dependent transmission coefficients that effectively analyzes conductance data in superconductor/ferromagnet contacts.

Findings

The model fits conductance data across voltage, temperature, and magnetic field.

The degree of spin polarization can be unambiguously determined from Andreev reflection.

The study advances understanding of spin transport in nanostructured ferromagnetic contacts.

Abstract

We present a study of the Andreev reflections in superconductor/ferromagnet nanostructured point contacts. The experimental data are analyzed in the frame of a model with two spin-dependent transmission coefficients for the majority and minority charge carriers in the ferromagnet. This model consistently describes the whole set of conductance measurements as a function of voltage, temperature, and magnetic field. The ensemble of our results shows that the degree of spin polarization of the current can be unambiguously determined using Andreev physics.