Ballistic conductance of magnetic Co and Ni nanowires with ultrasoft pseudo-potentials

TL;DR

This paper extends a scattering-based method to calculate ballistic conductance in magnetic transition metal nanowires using ultrasoft pseudo-potentials, revealing electron transmission behaviors at the Fermi level.

Contribution

It introduces a generalized approach for magnetic transition metals and applies it to Co and Ni nanowires with magnetization reversal, highlighting electron transmission characteristics.

Findings

$d$ electron conductance is blocked at Fermi energy due to magnetization reversal

$s$ electrons are perfectly transmitted at the Fermi level

Ni nanowires show higher transmission than Co nanowires below the Fermi level

Abstract

The scattering-based approach for calculating the ballistic conductance of open quantum systems is generalized to deal with magnetic transition metals as described by ultrasoft pseudo-potentials. As an application we present quantum-mechanical conductance calculations for monatomic Co and Ni nanowires with a magnetization reversal. We find that in both Co and Ni nanowires, at the Fermi energy, the conductance of $d$ electrons is blocked by a magnetization reversal, while the $s$ states (one per spin) are perfectly transmitted. $d$ electrons have a non-vanishing transmission in a small energy window below the Fermi level. Here, transmission is larger in Ni than in Co.