Repeated output coupling of ultracold Feshbach molecules from a Cs BEC

TL;DR

This paper demonstrates repeated output coupling of ultracold Cs Feshbach molecules from a BEC using magnetic field gradients, achieving multiple pulses and precise control over molecular cloud dynamics.

Contribution

It introduces a novel method for repeated molecule output coupling from a BEC via magnetic field gradient manipulation near a Feshbach resonance.

Findings

Up to 24 molecular pulses produced from a single condensate

Molecular pulses created every 7.2 ms

Controlled molecular dynamics via avoided crossing at 13.3 G

Abstract

We investigate magnetoassociation of ultracold Feshbach molecules from a Bose- Einstein condensate of Cs atoms and explore the spectrum of weakly bound molecular states close to the atomic threshold. By exploiting the variation of magnetic field experienced by a molecular cloud falling in the presence of a magnetic field gradient, we demonstrate the repeated output coupling of molecules from a single atomic cloud using a Feshbach resonance at 19.89 G. Using this method we are able to produce up to 24 separate pulses of molecules from a single atomic condensate, with a molecular pulse created every 7.2 ms. Furthermore, by careful control of the magnetic bias field and gradient we are able to utilise an avoided crossing in the bound state spectrum at 13.3G to demonstrate exquisite control over the dynamics of the molecular clouds.