Exploring Glassy Physics using Athermal Simulations

Thermal hard spheres simulations are widely used for probing the low temperature physics of glass formers. However, they suffer from the limitations of Monte-Carlo simulations, which are necessarily slow and not easily parallelizable. Although hard sphere interactions present infinitely strong repulsion upon contact, in the infinite pressure limit when the jamming transition occurs, mean-field theory predicts an effective potential, which is a logarithmic function of the gap between particles. This effective potential can be seen as a proxy for frequent collisions, acting as a measure of the allowed space each particle can travel before interacting with one of its neighbors. Thus, by studying the properties of this effective potential we can learn about the thermal system in a high pressure regime which is otherwise inaccessible. Using deterministic minimization schemes to find local minima of the free energy landscape, we can reach extremely dense configurations. We explore the features of such configurations, comparing their vibrational properties with their thermal counterparts as well as with mean field predictions. Furthermore, their dynamics have been tested using thermal simulations with the aim of using them as valid configurations of low temperature glasses.