Generation and dynamics of a degenerate CsYb mixture

We probe the collective dynamics of a quantum degenerate Bose-Bose mixture of Cs and ¹⁷⁴Yb with attractive interspecies interactions. Specifically, we excite vertical center of mass oscillations of the Cs condensate, and 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. We further explore the stability of the mixture by tuning the interaction strength of Cs using a broad Feshbach resonance, and observe collapse of the Cs condensate mediated by the attractive Cs-Yb interaction. Numerical simulations based on coupled Gross-Pitaevskii equations provide good agreement with experiment. We will report on recent progress from the Durham CsYb experiment including implementation of Cs-blind optical potentials.  We will discuss prospects for exploiting the unique advantages of Cs-Yb mixtures for studies of beyond-mean-field physics, including mass-imbalanced quantum liquid droplets where quantum fluctuations stabilise against mean-field collapse.