Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 58: Poster Session III (Solid-liquid interfaces; Scanning probe and other methods; Electronic structure theory; Spin-orbit interaction)

O 58.86: Poster

Mittwoch, 13. März 2013, 18:15–21:45, Poster B1

Investigation of spin-polarized transmission for electrons through Co/diamond/Co junctions — •Felix Huerkamp, Peter Krüger, and Johannes Pollmann — Institut für Festkörpertheorie, Universität Münster, Germany

We investigate the transmission properties of spin-polarized electrons at the interfaces of the metal-semiconductor hybrid system cobalt/diamond/cobalt within density-functional theory employing the generalized gradient approximation. The considered open system consists of three parts: the left and right semi-infinite cobalt leads, as well as the scattering region build by N layers of carbon atoms in a diamond structure. We use a Greens function technique which is based on the representation of the wave functions by Gaussian orbitals. This enables us to treat the scattering problem as a localized perturbation of a Co crystal. We have investigated junctions of hexagonal Co with C layers grown in (111) direction, as well as junctions of fcc Co with C layers oriented in (001) direction. We have identified different mechanisms, such as transmission resonances and overlapping interface states, that cause for specific energies and wave vectors a high transmission through the diamond layers. On the other hand, we find a vanishing transmission for energies within the Co bands and the diamond band gap at particular wave vectors even for thin C barriers. The results are discussed in dependence on the spin-direction and the number of carbon interlayers for hcp, as well as fcc Co leads.