Glassy dynamics of dense active granular matter with many-body particle interactions

Extending the understanding of disordered solids from idealized particle systems to real-world materials can be challenging due to the complexity in particle interactions. In this work, we investigate how many-body particle interactions influence the glassy dynamics of a dense packing of active granular particles. With an uplifting air flowing through a two-dimensional layer of pentagon-shaped granular particles, we induce a many-body aerodynamic interaction among particles. By controlling particle shapes, this many-body interaction can be tuned from being repulsive to attractive. In quiescent systems, we locate a glassy regime where particles are caged as indicated by a plateaued mean squared displacement. In this regime, we then probe how the many-body interactions alter the system's energy landscape via small amplitude cyclic deformation. The results are compared to molecular dynamic simulations with a similarly tunable many-body interaction for better understanding the relation between particle interaction and the ruggedness of the energy landscape.