Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 40: Poster II: Bio- and Molecular Magnetism (1-9); Magnetic Coupling Phenomena/Exchange Bias (10-15); Magnetic Particlicles and Clusters (16-29); Micro and Nanostructured Magnetic Materials (30-51); Multiferroics (52-64); Spin Injection in Heterostructures (65-67); Spin-Dyn./Spin-Torque (68-93); Spindependent Transport (94-108)

MA 40.17: Poster

Freitag, 27. März 2009, 11:00–14:00, P1A

Kondo effect in a magnetic trimer — •Philipp Knake and Alexander Chudnovskiy — 1. Institut für Theoretische Physik, Universität Hamburg

The system under consideration is a magnetic trimer on a metallic substrate. To describe it, we use an Anderson model in the low energy sector and in mean field theory. The spin degrees of freedom are taken into account by a fermionisation method first suggested by Popov and Fedotov. While for one single magnetic impurity the physics will be governed by the Kondo-effect, in the case of the magnetic trimer there additionally occur geometric effects (related to the RKKY effect). Instead of just one Kondo-temperature characterising the system of a single atom, there arise three characteristic temperatures in the latter case, the highest determining the physics. For some special geometries of the trimer, like the equilateral triangle and the linear chain, one can solve the mean field equations analytically in some limiting cases and thus achieve analytical expressions for the characteristic temperatures.