Regensburg 2010 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 8: CE: (General) Theory
TT 8.13: Talk
Monday, March 22, 2010, 17:15–17:30, H21
Two-particle response functions for multi-band Hubbard models — •Ernst von Oelsen1, Jörg Bünemann2, and Götz Seibold1 — 1BTU Cottbus, Lehrstuhl für Theoretische Physik, Cottbus — 2Philipps Universität Marburg, Fakultät für Physik, Marburg
In various studies on single-band Hubbard models, see, e.g., Ref. [1,2], the time-dependent Gutzwiller theory has been shown to be a valuable tool for the investigation of frequency and wave-vector dependent two-particle response functions. We have successfully generalised this approach for the study of arbitrary multi-band Hubbard models. With our new approach it is now possible to investigate such response functions, as e.g., the magnetic susceptibility for realistic three-dimensional multi-band models. This opens the way for a better understanding of various experimental results on systems with medium or strong Coulomb-interaction effects. In our presentation, we give a brief introduction to our theoretical approach and outline its prospects for future studies of real materials. As a first application, we show results for the magnetic susceptibility and the spin-wave properties of a two-band Hubbard model. We compare our findings with those of a Hartree-Fock based random-phase approximation, which is the standard textbook method for the calculation of two-particle response functions.
1 G. Seibold, J. Lorenzana, PRL 94, 107006 (2005)
2 G. Seibold, F. Becca, J. Lorenzana, PRL 100, 016405 (2008)