Rapid phase-diffusion between atomic and molecular Bose-Einstein condensates

TL;DR

This paper investigates the rapid phase diffusion in atom-molecule coherence within Bose-Einstein condensates, revealing that collisional losses cause faster decoherence in atom-molecule systems compared to atomic condensate splitting.

Contribution

It demonstrates that atom-molecule coherence exhibits faster phase diffusion due to the nature of the generated two-atom states, highlighting fundamental differences in coherence dynamics.

Findings

Atom-molecule coherence undergoes faster phase diffusion than atomic condensate splitting.

The study quantifies the difference in phase-diffusion rates as a factor of .

Two-atom states are identified as SU(1,1) coherent states with linear number variance.

Abstract

We study the collisional loss of atom-molecule coherence after coherently dissociating a small fraction of a molecular Bose-Einstein condensate into atoms. The obtained $n$-atoms states are two-atom (SU(1,1)) coherent states with number variance $\Delta n\propto n$ compared to $\Delta n\propto \sqrt{n}$ for the spin (SU(2)) coherent states formed by coherent splitting of an atomic condensate. Consequently, the Lorentzian atom-molecule phase-diffusion is faster than the Gaussian phase-diffusion between separated atomic condensates, by a $\sqrt{n}$ factor.