Berlin 2008 – scientific programme

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O: Fachverband Oberflächenphysik

O 65: Methods: Theory and Experiment

O 65.4: Talk

Thursday, February 28, 2008, 12:45–13:00, MA 141

Electronic transport over single atoms — •Martyna Polok, Dmitry V. Fedorov, Peter Zahn, and Ingrid Mertig — Department of Physics, Martin Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany

Scanning Tunneling Microscope (STM) experiments are important examples of the tunneling through single atoms. We try to develop a general understanding of the transport phenomena in complex structures through a case study of the STM setup.

The density functional theory (DFT) in the Korringa-Kohn-Rostoker (KKR) Green's function formulation is implemented to obtain the ground state electronic structure of the system. The transport properties are calculated in the linear response limit using the Baranger and Stone formalism.

In our ab initio investigation we consider a Cu and Co STM tip approaching a Cu (001) surface decorated with a single Cu or Co adatom. Depending on the chemical and geometrical structure of the constriction different transport channels contribute to the total conductance. Based on the spatial current distribution we can classify the open eigenchannels according to the symmetry of different angular momentum contributions i.e. the type of valence orbitals available at the Fermi energy.

The aim of this work is to demonstrate the interplay between the structure of the constriction and the electronic transport properties.