Dynamics of a vibrated granular raft with many-body capillary attraction

The dynamics of a granular system can be affected by complicated factors, including the level of disorder within the packing structure and many-body particle interactions, which influence the ruggedness of the system's energy landscape. Here, we study the dynamics of a disordered granular raft where particles reside at an air-liquid interface and have many-body interactions due to capillary attraction and hydrodynamics. For given particle and liquid properties, we quantify many-body effects by observing the approaching dynamics of a handful of nearby floating particles, where the attraction between two particles is noticeably influenced by the presence of a third. In a dense granular raft, we use vertical vibration to induce quasi-thermal motion in the particles, controlling initial packing structure and disorder in the system. By tuning vibration amplitude and frequency, we locate a dense regime without large scale voids in which particles have random motion and the raft exhibits glassy behavior. Tuning the particle interaction potential, we analyze the effects of initial disorder and many-body interactions on the glassy dynamics of our system.