Structure and Dynamics of Bulk and Confined Active Matter via Excess Entropy Scaling

Active matter is composed of self-driven units that can convert stored or ambient free energy into motion. Systems containing active particles exhibit a fascinating array of transport phenomena, which are altogether distinct from their inactive counterparts. In this talk, building upon our recent work in this area, we present evidence that there exist robust excess entropy scaling relations that directly connect activity-modified transport coefficients with the static structure of an active system. These relations are in nearly direct analogy with excess entropy scaling results for binary fluid mixtures at equilibrium. Motivated by recent experimental developments in confined active matter, we also present results that highlight the interplay between activity and confinement in terms of structure, transport, phase segregation, and the applicability of excess entropy scaling relations. Throughout, we validate our results against extensive molecular-dynamics simulations, in which we vary the total fraction of active particles, the degree of activity for active particles, and various geometric factors.