Title: Topological persistence near jamming

Author (Poster): Adam Abate, Penn Physics

Abstract:

The dynamics of pre-jammed systems are reminiscent of dense-colloidal suspensions, thermal glasses, and supercooled liquids since the same telltale features develop in the structure and dynamics near jamming. Yet, no single measurement has directly related the structural changes to the dynamical ones. To that end we quantify temporal fluctuations due to persistent topological heterogeneities. Based on the Voronoi tessellation we define the persistent area. By quantifying its temporal fluctuations we quantify the system's persistent spacial correlations. Based on the Delaunay triangulation we define a persistent bond in which particles that are nearest neighbors are defined to be bonded together. Tracking how nearest neighbor bonds change with time we quantify the breakup of immobile clusters and the greater relaxation of the system. Both measurements lead to growing length scales on approach to jamming. These persistent topological features therefore provide two independent and direct ways of relating how a nearly jammed system's structure influences its dynamics.