236 research outputs found
Anharmonicity Induced Resonances for Ultracold Atoms and their Detection
When two atoms interact in the presence of an anharmonic potential, such as
an optical lattice, the center of mass motion cannot be separated from the
relative motion. In addition to generating a confinement-induced resonance (or
shifting the position of an existing Feshbach resonance), the external
potential changes the resonance picture qualitatively by introducing new
resonances where molecular excited center of mass states cross the scattering
threshold. We demonstrate the existence of these resonances, give their
quantitative characterization in an optical superlattice, and propose an
experimental scheme to detect them through controlled sweeping of the magnetic
field.Comment: 6 pages, 5 figures; expanded presentatio
Effective low-dimensional Hamiltonian for strongly interacting atoms in a transverse trap
We derive an effective low-dimensional Hamiltonian for strongly interacting
ultracold atoms in a transverse trapping potential near a wide Feshbach
resonance. The Hamiltonian includes crucial information about transverse
excitations in an effective model with renormalized interaction between atoms
and composite dressed molecules. We fix all the parameters in the Hamiltonian
for both one- and two-dimensional cases.Comment: v2: 5 pages, 1 figure; expanded presentation of the formalis
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