Dresden 2009 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 9: Correlated Electrons: Metal-Insulator Transition 1

TT 9.2: Vortrag

Montag, 23. März 2009, 14:15–14:30, HSZ 03

Correlation effects in half-metallic Heusler alloys — •Eberhard Jakobi, Nils Blümer, and Peter van Dongen — KOMET337, Institut für Physik, Johannes Gutenberg-Universität Mainz, Deutschland

Spintronic applications such as giant magnetoresistive or spin valve devices require materials with high spin polarization, ideally half metals at room temperature. Heusler alloys are an important class of candidates for such spintronic materials [1].

For these moderately correlated materials, density functional theory (DFT) appears as a reasonable starting point [2]. However, this description lacks lifetime effects and cannot exhibit Mott transitions.

We present results within dynamical mean-field theory (DMFT), obtained using a second-order weak-coupling impurity solver, which is optimized for treating systems with a large number of valence bands. Correlation effects lead to significant changes in the band-selective densities of states and to corrections in the local moments.

[1] Wurmehl et al, Appl. Phys. Lett. 88 (2006) 032503

[2] Kandpal et al, J. Phys. D: Appl. Phys. 40 (2007) 1507