Regensburg 2010 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 28: Surface or interface magnetism

O 28.7: Vortrag

Dienstag, 23. März 2010, 12:00–12:15, H48

Switching a single spin on metal surfaces: ab initio studies — •Kun Tao¹, Valeri.S Stepanyuk¹, Wolfram Hergert², Ivan Rungger³, Stefano Sanvito³, and Patrick Bruno⁴ — ¹Max-Planck-Institute of Microstructure Physics, Halle, Germany — ²Fachbereich Physik, Martin-Luther-University, Halle-Wittenberg, Friedemann-Bach-Platz 6, D-06099 Halle, Germany — ³School of Physics and CRANN, Trinity College, Dublin 2, Ireland — ⁴European Synchrotron Radiation Facility, F-38043 Grenoble Cedex, France

We perform ab initio calculations of the the exchange coupling between single magnetic adatoms adsorbed on metal surfaces and a spin polarized STM tip. We apply density functional theory (DFT) based methods and perform calculations in the fully relaxed geometries for the tip and the substrate. We demonstrate that the spin direction of single adatoms can be controlled by varying the tip-substrate distance. The sign of the exchange energy is determined by the competition of the direct and the indirect interactions between the tip and the adatom[1]. Based the nonequilibrium Green function method, we perform the spin-dependent transport calculations and find a large magnetoresistance of the junction at short tip-substrate distances.

[1] Kun Tao, V.S. Stepanyuk, W. Herget, I. Rungger, S. Sanvito, P. Bruno, Phys. Rev. Lett 103, 057202 (2009)