Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 37: MLT: Poster Session

TT 37.9: Poster

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

Lattice small polaron theory for Bose-Fermi mixtures — •Antonio Privitera, Mohammad Reza Bakhtiari, and Walter Hofstetter — Institut für Theoretische Physik, Johann Wolfgang Goethe-Universität, 60438 Frankfurt am Main, Germany

We present a generalization of small polaron theory describing polaronic effects in strongly imbalanced Bose-Fermi mixtures in the case where both Bosons and Fermions are trapped in the same optical lattice [1]. This allows us to estimate how the hopping of a single Fermionic impurity immersed in a large BEC is renormalized for different temperatures and coupling regimes. The presence of a lattice strongly affects the properties of the Bogolubov modes, which play the same role as phononic excitations in the context of condensed matter physics. We show that these lattice effects cannot be simply included within a mass renormalization, even at zero temperature. Finally we discuss the limits of validity of the approach and compare our results with recent experiments on strongly imbalanced Bose-Fermi mixtures.

[1] T. Best et al., Phys. Rev. Lett. 102, 030408 (2009)