Berlin 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 15: Correlated Electrons: Quantum Impurities, Kondo Physics 1

TT 15.3: Vortrag

Montag, 26. März 2012, 17:15–17:30, BH 334

NRG calculations of the magnetization of isotropic and anisotropic Kondo impurities — •Martin Höck and Jürgen Schnack — Universität Bielefeld, Fakultät für Physik, Bielefeld, Germany

The deposition of magnetic molecules on suitable substrates renders the addressing and thus manipulation of individual molecules possible and might facilitate their use for information storage or quantum computing purposes. However, the magnetic properties of the molecules, which are crucial for the proposed applications, will in general be influenced by the interaction with the substrate. Our goal is to better understand the form and extent of this effect by studying simplified model systems.

To this end, we perform Numerical Renormalization Group (NRG) calculations for single-impurity Kondo models with additional uniaxial anisotropy and a local or bulk magnetic field. The impurity part of the model might thus serve as a minimal representation of a magnetic molecule. We focus on the impurity magnetization, which has been measured in a number of experiments using XMCD and STM, and study its dependence on temperature and applied field for different anisotropy parameters. In case of a “hard axis” anisotropy, the magnetic field can lead to effective groundstate degeneracies and can therefore induce Kondo screening effects.