Impact of overlapping resonances on magnetoassociation of cold molecules in tight traps

TL;DR

This paper develops an effective theoretical framework to understand how overlapping Feshbach resonances affect magnetoassociation of ultracold molecules in traps, revealing regimes where traditional models fail.

Contribution

It introduces a new approach to describe magnetoassociation with multiple overlapping resonances in external traps, extending beyond conventional two-channel Landau-Zener models.

Findings

Overlapping resonances significantly alter energy level structures.

Trap parameters influence the effectiveness of molecule production.

A regime exists where Landau-Zener approximation no longer applies.

Abstract

Overlapping Feshbach resonances are commonly observed in experiments with ultracold atoms and can influence the molecule production process. We derive an effective approach to describe magnetoassociation in an external trap in the presence of multiple overlapping resonances. We study how the strength and shape of the trap affects the energy level structure and demonstrate the existence of a regime in which the conventional two-channel Landau-Zener description of the molecule production process breaks down.