Non-adiabatic dissociation of molecules and BEC loss due to shock-waves

TL;DR

This paper introduces a phenomenological model explaining atom loss in BECs near Feshbach resonances as caused by non-adiabatic molecular dissociation from shock-waves, matching experimental scaling behaviors.

Contribution

It proposes a simple two-parameter model for shock-wave induced molecular dissociation, providing a new understanding of BEC loss mechanisms near Feshbach resonances.

Findings

Model accurately describes experimental loss scaling

Identifies shock-waves as a key dissociation mechanism

Predicts parameters for future experimental testing

Abstract

Recent experiments have shown the likely appearance of coherent BEC atom-molecule oscillations in the vicinity of a Feshbach resonance. In addition, a new loss mechanism was observed, whereby the loss of atoms from the BEC is inversely dependent on the rate of change of the applied magnetic field. We present here a phenomenological model which gives a good description of the scaling properties of this new decay process, by attributing it to non-adiabatic dissociation of molecules by a propagating shock-wave. The model has only two free parameters, which specify the size of the "shocked-region", and can be readily tested by future experiments.