Regensburg 2010 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 32: MLT: Quantum Liquids, Bose-Einstein Condensates, Ultra-cold Atoms, ... 2

TT 32.1: Talk

Thursday, March 25, 2010, 14:00–14:15, H18

Interaction Quenches of Fermi Gases — •Götz S. Uhrig — Lehrstuhl Theoretische Physik I, TU Dortmund, 44221 Dortmund

Progress in the manipulation of fermionic atoms in optical lattices makes it possible to switch interactions at will. So non-equilibrium issues gain increasing interest. It is shown that the jump in the momentum distribution of Fermi gases evolves smoothly for small and intermediate times once an interaction between the fermions is suddenly witched on. The jump does not vanish abruptly. Explicit calculations are possible for the Tomonaga-Luttinger model with and without spin. For general interacting models in arbitrary dimension the structure of the equations of motion in the Heisenberg picture is analyzed. It is found that the loci in momentum space where the jumps occur are those of the noninteracting Fermi sea. No relaxation of the Fermi surface geometry takes place.