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Q: Fachverband Quantenoptik und Photonik
Q 12: Ultra-cold atoms, ions and BEC (with A)
Q 12.3: Poster
Montag, 29. Februar 2016, 16:30–19:00, Empore Lichthof
Orbital magnetism of ultracold fermionic gases in a lattice: Dynamical Mean-Field Approach — •Agnieszka Cichy1, Anna Golubeva1, Andrii Sotnikov2, and Walter Hofstetter1 — 1Goethe Universität, Frankfurt a. M., Germany — 2Kharkiv Institute of Physics and Technology, Kharkiv, Ukraine
The impressive development of experimental techniques in ultracold quantum degenerate gases of alkaline-earth-like atoms in the last years has allowed investigation of strongly correlated systems. Long-lived metastable electronic states in combination with decoupled nuclear spin give the opportunity to study the Hamiltonians beyond the possibilities of current alkali-based experiments. Ytterbium is particularly convenient due to its large number of bosonic and fermionic (e.g. 173Yb) isotopes with a wide range of interaction strengths.
We study finite-temperature properties of the two-band Hubbard model on a simple cubic lattice. Our main goal is to investigate the role of exchange interaction in finite temperature magnetic phases, for the whole range of fillings. We use the Dynamical Mean-Field Theory approach and its extension in real space to obtain finite-temperature phase diagrams including transitions to magnetically-ordered phases. We determine which parameter regimes are most favourable for ferromagnetism, in terms of experimental observation in ultracold atomic gases in a lattice. We also calculate the entropy in the vicinity of magnetically-ordered phases that allows to make important predictions for on-going and future experiments aiming at approaching and studying long-range ordered states in ultracold atomic mixtures.