Dresden 2009 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 41: Matter at Low Temperature: Quantum Liquids, Bose-Einstein-Condensates, Ultra-cold Atoms

TT 41.9: Talk

Thursday, March 26, 2009, 16:15–16:30, HSZ 105

Real-Space Dynamical Mean-Field Theory for Strongly Correlated Atoms — •Michiel Snoek, Irakli Titvinidze, and Walter Hofstetter — Institut für Theoretische Physik, Goethe-Universitaet Frankfurt

To describe strongly interacting atoms in an inhomogeneous optical lattice, we apply Real-Space Dynamical Mean-Field Theory (R-DMFT). R-DMFT captures the effects of strong correlations and spatial inhomogeneity in a unified, non-perturbative framework. Local correlations are taken into account exactly.

We apply this numerical scheme to antiferromagnetic states of repulsively interacting fermions with spin 1/2 in a harmonic potential. Within R-DMFT, antiferromagnetic order is found to be stable in spatial regions with total particle density close to one, but persists also in parts of the system where the local density significantly deviates from half filling. In systems with spin imbalance, we find that antiferromagnetism is gradually suppressed and phase separation emerges beyond a critical value of the spin imbalance.

We also investigate trapped Bose-Fermi mixtures in an optical lattice with R-DMFT. We look for the effect of the fermions on the bosonic visibility and analyze the stability of a supersolid in an harmonic trap.