Mimicking multi-channel scattering with single-channel approaches

Abstract

The collision of two atoms is an intrinsic multi-channel (MC) problem as becomes especially obvious in the presence of Feshbach resonances. Due to its complexity, however, single-channel (SC) approximations, which reproduce the long-range behavior of the open channel, are often applied in calculations. In this work the complete MC problem is solved numerically for the magnetic Feshbach resonances (MFRs) in collisions between generic ultracold 6Li and 87Rb atoms in the ground state and in the presence of a static magnetic field B. The obtained MC solutions are used to test various existing as well as presently developed SC approaches. It was found that many aspects even at short internuclear distances are qualitatively well reflected. This can be used to investigate molecular processes in the presence of an external trap or in many-body systems that can be feasibly treated only within the framework of the SC approximation. The applicability of various SC approximations is tested for a transition to the absolute vibrational ground state around an MFR. The conformance of the SC approaches is explained by the two-channel approximation for the MFR.

15 pages, 10 figures

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• Feshbach resonances in mixtures of ultracold ${}^6$Li and ${}^{87}$Rb gases
• Feshbach resonances in an ultracold ${}^7$Li and ${}^{87}$Rb mixture
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• Influence of a tight isotropic harmonic trap on photoassociation in ultracold homonuclear alkali gases
• Two-channel model of photoassociation in the vicinity of a Feshbach resonance

Cited by in corpus (3)

• Coherent molecule formation in anharmonic potentials near confinement-induced resonances
• Theory of inelastic confinement-induced resonances due to the coupling of center-of-mass and relative motion
• Theoretical description of two ultracold atoms in finite 3D optical lattices using realistic interatomic interaction potentials