Dynamics of the unitary Bose gas near a narrow Feshbach resonance: universal coherent atom-molecule oscillations

Kavli Affiliate: Ke Wang

| First 5 Authors: Ke Wang, Zhendong Zhang, Shu Nagata, Zhiqiang Wang, K. Levin

| Summary:

Quench experiments on a unitary Bose gas around a broad Feshbach resonance
have led to the discovery of universal dynamics. This universality is
manifested in the measured atomic momentum distributions where, asymptotically,
a quasi-equilibrated metastable state is found in which both the momentum
distribution and the time scales are determined by the particle density. In
this paper we present counterpart studies but for the case of a very narrow
Feshbach resonance of $^{133}$Cs atoms having a width of 8.3 mG. In dramatic
contrast to the behavior reported earlier, a rapid quench of an atomic
condensate to unitarity is observed to ultimately lead to coherent oscillations
involving dynamically produced condensed and non-condensed molecules and atoms.
The same characteristic frequency, determined by the Feshbach coupling, is
observed in all types of particles. To understand these quench dynamics and how
these different particle species are created, we develop a beyond
Hartree-Fock-Bogoliubov dynamical framework including a new type of cross
correlation between atoms and molecules. This leads to a quantitative
consistency with the measured frequency. Our results, which can be applied to
the general class of bosonic superfluids associated with narrow Feshbach
resonances, establish a new paradigm for universal dynamics dominated by
quantum many-body interactions.

| Search Query: ArXiv Query: search_query=au:”Ke Wang”&id_list=&start=0&max_results=3

Read More