Transmission through correlatedCunCoCunheterostructures

C Morari,L Chioncel,A Östlin,W H Appelt,A Droghetti,U Eckern,I Rungger,L Vitos,A V Postnikov,M M Radonjić

doi:10.1103/physrevb.92.054431

Abstract

The effects of local electronic interactions and finite temperatures upon the transmission across the Cu$_4$CoCu$_4$ metallic heterostructure are studied in a combined density functional and dynamical mean field theory. It is shown that, as the electronic correlations are taken into account via a local but dynamic self-energy, the total transmission at the Fermi level gets reduced (predominantly in the minority spin channel), whereby the spin polarization of the transmission increases. The latter is due to a more significant $d$-electrons contribution, as compared to the non-correlated case in which the transport is dominated by $s$ and $p$ electrons.

Highlights

The design of multilayered heterostructures composed of alternating magnetic and nonmagnetic metals offers large flexibility in tailoring spin-sensitive electron transport properties of devices in which the current flow is perpendicular to the planes
The exact muffin-tin orbitals (EMTO) code, in its turn, uses the muffin-tin construction; we present a detailed description of the projection of quantities such as the many-body self-energy from the EMTO basis set into the numerical atomic orbitals (NAOs) basis set (SMEAGOL/SIESTA) in Sec
We discuss the changes in the electronic structure and in the conductance of a single Co layer sandwiched between semi-infinite Cu electrodes caused by the inclusion of the Coulomb interaction at the generalized gradient approximation (GGA)+dynamical mean field theory (DMFT) level

Summary

Introduction

The design of multilayered heterostructures composed of alternating magnetic and nonmagnetic metals offers large flexibility in tailoring spin-sensitive electron transport properties of devices in which the current flow is perpendicular to the planes. In order to maximize the spin polarization of current and the GMR, heterostructures including half-metallic materials [3,4,5] seem to be the materials of choice. The ballistic transport properties have been addressed by considering the Landauer-Buttiker formalism [6,7,8,9], where the conductance is determined by the electron transmission probability through the device region, which is placed between two semi-infinite electrodes.

Methods

Results

Conclusion