Hannover 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
Q: Fachverband Quantenoptik und Photonik
Q 38: Quantum Gases: Bosons III / Lattices I
Q 38.8: Vortrag
Mittwoch, 10. März 2010, 18:15–18:30, E 001
Paired and Usual Superfluidity in Spin-1 Optical Lattices — •Leonardo Mazza1, Matteo Rizzi1, Maciej Lewenstein2, and J.Ignacio Cirac1 — 1Max-Planck Institut für Quantenoptik, Garching, Deutschland — 2ICREA and ICFO, Barcelona, Spain
We discuss the possibility of simulating three-body repulsive contact interactions using experimentally feasible ultracold atoms setups. In particular, we consider a spin-1 (F=1) atomic Mott insulator (MI) with one atom per site, whose three local degrees of freedom are mapped into local bosonic occupation numbers less than two. This simulates a system with infinite three-body repulsion and null two-body interaction. Suitable laser assisted couplings via an auxiliary F=2 ancilla tailor the ratio between single-particle and pair-correlated hopping.
This suggests to explore an enriched phase diagram where also a pair-superfluid (PSF) is present. First of all, we investigate the transition between the usual superfluid phase (SF) and the paired one as a function of particle density and ratio of the two hopping parameters. Numerics is performed in 1D with DMRG and algebraic decay of correlations is exploited to discriminate the phases.
Finally, we move on to the theoretical Hubbard model with the insertion of the pair-correlated hopping term. Besides the usual MI for dominating two-body repulsion, and SF phase for prevailing single-particle hopping parameter, a collapsed phase emerges when the paired hopping is leading. This strongly restricts the PSF region of the phase diagram, and motivates resorting to the previous experimental proposal in order to observe such an exotic phase.