Calculations of spin induced transport in ferromagnets

TL;DR

This paper introduces a first-principles computational method using the tetrahedron technique to accurately evaluate spin polarization in ferromagnets, applicable to both ballistic and diffusive transport regimes.

Contribution

It presents a novel, efficient approach for calculating and analyzing spin polarization in ferromagnets from first principles, including contributions of different electronic states.

Findings

Validated method against Fe and Ni with high accuracy

Able to analyze electronic state contributions to spin transport

Explained discrepancies in CeMnNi4's spin polarization

Abstract

Based on first-principles density functional calculations, a general approach for determining and analyzing the degree of spin polarization (P) in ferromagnets is presented. The approach employs the so-called tetrahedron method to evaluate the Fermi surface integrations of P in both ballistic and diffusive regimes. The validity of the method is examined by comparing the calculated P values for Fe and Ni with the experiment. The method is shown to yield highly accurate results with minimal computational effort. Within our approach, it is also possible to systematically analyze the contributions of various types of electronic states to the spin induced transport. As a case study, the transport properties of the soft-ferromagnet CeMnNi4 are investigated in order to explain the origin of the existing difference between the experimental and theoretical values of P in this intermetallic compound.