How to calculate the degree of spin polarization in ferromagnets?

TL;DR

This paper reviews various methods to define and calculate spin polarization in ferromagnets, comparing theoretical approaches with experimental data for Fe and Ni, highlighting differences in definitions and measurement techniques.

Contribution

It provides a comparative analysis of different definitions of spin polarization and demonstrates their application to experimental data using LSDA calculations.

Findings

Different definitions of spin polarization can yield varying results.

Calculated spin polarization for Fe and Ni shows notable differences depending on the method.

The paper clarifies how measurement techniques influence the interpretation of spin polarization.

Abstract

Different ways to define and to calculate the degree of spin polarization in a ferromagnet are discussed, particularly with respect to spin-polarized tunneling and Andreev reflection at the boundary between a superconductor and ferromagnet. As an example, the degrees of spin polarization for different experiments in Fe and Ni are calculated in the framework of the local spin density approximation (LSDA) and used to illustrate the differences between various definitions of spin polarization.