Microscopic theory of atom-molecule oscillations in a Bose-Einstein condensate

TL;DR

This paper presents a microscopic theoretical analysis of atom-molecule oscillations in a Bose-Einstein condensate, explaining experimental observations and supporting the formation of a molecular condensate.

Contribution

It introduces a detailed microscopic model that explains the dynamics of atom-molecule oscillations and the formation of molecular condensates near a Feshbach resonance.

Findings

The theory reproduces the experimental oscillatory behavior.

It identifies the physical properties of the produced components.

Supports the existence of a molecular condensate in the experiment.

Abstract

In a recent experiment at JILA [E.A. Donley et al., Nature (London) 417, 529 (2002)] an initially pure condensate of Rb-85 atoms was exposed to a specially designed time dependent magnetic field pulse in the vicinity of a Feshbach resonance. The production of new components of the gas as well as their oscillatory behavior have been reported. We apply a microscopic theory of the gas to identify these components and determine their physical properties. Our time dependent studies allow us to explain the observed dynamic evolution of all fractions, and to identify the physical relevance of the pulse shape. Based on ab initio predictions, our theory strongly supports the view that the experiments have produced a molecular condensate.