Dynamics of a degenerate Cs-Yb mixture with attractive interspecies interactions

We probe the collective dynamics of a quantum degenerate Bose-Bose mixture of Cs-133 and Yb-174 with attractive interspecies interactions. Specifically, we excite vertical center-of-mass oscillations of the Cs condensate. We observe significant damping for the Cs dipole mode, due to the rapid transfer of energy to the larger Yb component and the ensuing acoustic dissipation. Numerical simulations based on coupled Gross-Pitaevskii equations provide excellent agreement with experiment and additionally reveal the possibility of late-time revivals (beating), which are found to be highly sensitive to the Cs and Yb atom number combinations. By further tuning the interaction strength of Cs using a broad Feshbach resonance, we explore the stability of the degenerate mixture. We observe collapse of the Cs condensate mediated by the attractive Cs-Yb interaction when a(Cs) < 50 a(0), well above the single-species collapse threshold, in good agreement with simulations.

Automated summary

In this study, we investigate the collective dynamics of a quantum degenerate Bose-Bose mixture of Cs-133 and Yb-174 with attractive interspecies interactions. The experiments and numerical simulations reveal complex and interesting behaviors, such as significant damping of the Cs dipole mode and the possibility of late-time revivals highly sensitive to Cs and Yb atom number combinations. Additionally, we explore the stability of the degenerate mixture and observe collapse of the Cs condensate mediated by the attractive Cs-Yb interaction under certain conditions, in good agreement with simulations.