Spin-polarized ballistic conduction through correlated Au-NiMnSb-Au heterostructures

TL;DR

This study investigates spin-polarized ballistic conduction in Au-NiMnSb-Au heterostructures, demonstrating how increasing layers enhances spin polarization and how local electronic interactions influence conduction properties.

Contribution

It provides new insights into the impact of layer number and many-body interactions on spin-polarized conduction in heterostructures.

Findings

Increasing NiMnSb layers enhances spin polarization of transmission.

Local electronic interactions cause hybridization affecting conduction.

Spin polarization in transmission remains high despite reduced density of states.

Abstract

We examine the ballistic conduction through Au-NiMnSb-Au heterostructures consisting of up to four units of NiMnSb in the scattering region. We investigate the dependence of the transmission function computed within the local spin density approximation (LSDA) of the density functional theory (DFT) on the number of half-metallic units in the scattering region. For a single NiMnSb unit the transmission function displays a spin polarization of around 50 % in a window of 1 eV centered around the Fermi level. By increasing the number of layers an almost complete spin polarization of the transmission is obtained in the same energy window. Supplementing the DFT-LSDA calculations with local electronic interactions, of Hubbard-type on the Mn sites, leads to a hybridization between the interface and many-body states. The significant reduction of the spin polarization seen in the density of states is not apparent in the spin-polarization of the conduction electron transmission, which suggests the localized nature of the hybridized interface and many-body induced states.