Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 34: Postersession Matter at Low Temperature: Quantum Liquids, Bose-Einstein Condensates, Ultra-Cold Atoms
TT 34.3: Poster
Mittwoch, 25. März 2009, 14:00–18:00, P1A
Real-space DMFT for inhomogeneous strongly correlated fermionic systems — •Irakli Titvinidze1, Michiel Snoek1, Csaba Toke1, Krzysztof Byczuk2, and Walter Hofstetter1 — 1Institut für Theoretische Physik, Goethe-Universität, D-60438 Frankfurt, Germany — 2Institute of Theoretical Physics, Warsaw University, ul. Hoża 69, 00-681 Warszawa, Poland
We introduce the real-space dynamical mean-field theory (R-DMFT) method to describe strongly interacting lattice fermions in the presence of an external, position dependent potential. This method relies only on the assumption that the self-energy is a local quantity, and is exact in infinite dimensions. Using R-DMFT we study an ultracold spin 1/2 fermionic atomic gas in an optical lattice. Using the numerical renormalization group (NRG) as an impurity solver we show that antiferromagnetic order is 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.