Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 45: Correlated Electrons: Poster Session

TT 45.93: Poster

Donnerstag, 29. März 2012, 15:00–19:00, Poster B

Perspectives of LDA+Slave-boson mean-field theory for realistic low-energy physics — •Christoph Piefke, Malte Behrmann, Sergej Schuwalow, and Frank Lechermann — 1. Institut für Theoretische Physik, Universität Hamburg

The rotationally invariant slave-boson mean-field theory (RISB) is used to investigate large parameter spaces of arbitrary strongly interacting systems [1,2,3] based on realistic LDA calculations [4,5]. The multiorbital Hubbard-Hamiltonian is mapped onto an itinerant quasiparticle part and localized bosonic degrees of freedom. This decouples complex interactions, quartic in the original electron-operators, at the cost of a set of constraints. At saddle-point, a self-consistent mean-field solution is obtained. Practical computations using RISB are limited by the fact that the degrees of freedom of the modelation grow exponentially with the number of correlated orbitals. To circumvent this limitation, one reduces the number of variational parameters using symmetries. We demonstrate some of the recently implemented techniques and improvements in the context of itinerant systems with magnetic degrees of freedom and/or geometric frustration.
Li, Wölfle, Hirschfeld, PRB 40, 6817 (1989).
Lechermann, Georges, Kotliar, Parcollet, PRB 76, 155102 (2007).
Lechermann, PRL 102, 046403 (2009).
Piefke, Boehnke, Georges, Lechermann, PRB 82, 165118 (2010).
Piefke, Lechermann, phys.stat. solidi (b) 248, 2269 (2011).