Contact network topology in tapped granular media

摘要

We analyze the contact network of simulated two-dimensional granular packings in different states ofnmechanical equilibrium obtained by tapping. We show that topological descriptors of the contact networknallow one to distinguish steady states of the same mean density obtained with different tap intensities. Thesenequal-density states were recently proven to be distinguishable through the mean force moment tensor. Inncontrast, geometrical descriptors, such as radial distribution functions, bond order parameters, and Voronoincell distributions, can hardly discriminate among these states. We find that small-order loops of contacts—thenpolygons of the network—are especially sensitive probes for the contact structure.