Jamming of polydisperse hard spheres: The effect of kinetic arrest

We study jammed configurations of polydisperse colloidal hard spheres with a well-defined temperature (constant kinetic energy) as a function of compression speed and size polydispersity. To this end, we employ event-driven molecular-dynamics simulations at fixed temperature, using an algorithm that strictly prohibits particle overlaps. We find a strong dependence of the jamming density on the compression rate that cannot be explained by crystallization. Additionally, we find that during the compression, the pressure follows the metastable liquid branch until the system gets kinetically arrested. Our results show that further compression yields jammed configurations that can be regarded as the infinite-pressure limit of glassy states and that different glasses can jam at different jamming densities depending on the compression rate. We present accurate data for the jamming density as a function of compression rate and size polydispersity.