Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 37: MLT: Poster Session

TT 37.13: Poster

Donnerstag, 25. März 2010, 14:00–18:00, Poster A

Dynamical mean-field theory for bose-fermi mixtures in optical lattices — •Krzysztof Byczuk¹ and Dieter Vollhardt² — ¹Institute of Theoretical Physics, University of Warsaw*, ul. Hoza 69, PL-00-681 WARSZAWA — ²Theoretical Physics III, Center for Electronic Correlations and Magnetism*, Institute of Physics, University of Augsburg*, D-86135 Augsburg, Germany

We derive a dynamical mean-field theory for mixtures of interacting bosons and fermions on a lattice (BF-DMFT) [1,2]. The BF-DMFT is a comprehensive, thermodynamically consistent framework for the theoretical investigation of Bose-Fermi mixtures and is applicable for arbitrary values of the coupling parameters and temperatures. It becomes exact in the limit of high spatial dimensions d or coordination number Z of the lattice. In particular, the BF-DMFT treats normal and condensed bosons on equal footing and thus includes the effects caused by their dynamic coupling. Using the BF-DMFT we investigate two different interaction models of correlated lattice bosons and fermions, one where all particles are spinless (model I) and one where fermions carry a spin one-half (model II). In model I the local, repulsive interaction between bosons and fermions can give rise to an attractive effective interaction between the bosons. In model II it can also lead to an attraction between the fermions.

[1] K. Byczuk and D. Vollhardt, Phys. Rev. B 77, 235106 (2008)

[2] K. Byczuk and D. Vollhardt, Ann. Phys. (Berlin) 18, 622 (2009)