Two-channel model description of confinement-induced Feshbach molecules

TL;DR

This paper presents a two-channel theoretical model for confinement-induced Feshbach molecules, highlighting deviations from single-channel predictions especially for narrow resonances, and provides results that align with experimental data.

Contribution

The study introduces a comprehensive two-channel model including bare interatomic interactions, improving accuracy over previous single-channel approaches for confinement-induced molecules.

Findings

Two-channel model predicts larger deviations for narrow resonances.

Including bare interactions significantly affects binding energy calculations.

Results agree with existing experimental data and suggest future experimental tests.

Abstract

Using a two-channel model, we investigate theoretically the binding energy of confinement-induced Feshbach molecules in two- and one-dimensional ultracold atomic systems, near a Feshbach resonance. We show that the two-channel prediction will evidently deviate from the simple single-channel theory as the width of Feshbach resonances decreases. For one-dimensional system, we perform a full two-channel calculation, with the inclusion of bare interatomic interactions in the open channel. Away from the resonance, we find a sizable correction to the binding energy, if we neglect incorrectly the bare interatomic interactions as in the previous work [Dickerscheid and Stoof, Phys. Rev. A 72, 053625 (2005)]. We compare our theoretical results with existing experimental data and present predictions for narrow Feshbach resonances that could be tested in future experiments.