Waiting-time distributions of particle entrapments in clustered states generated by short-range attractive, long-range repulsive (SALR) interactions

¹ Department of Chemistry and Molecular Biology, University of Gothenburg - SE-412 96, Göteborg, Sweden
² Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware Newark, DE 19711, USA

Received: 20 February 2019
Accepted: 7 May 2019

Abstract

Brownian dynamics simulations have been carried out for so-called SALR systems, comprising fluids of particles interacting via competing short-range attractions and long-range repulsions. As the attraction is strengthened, particles form long-lived clusters with an internal structure that becomes ordered. This process is correlated with a slowing-down of the dynamics, which shows subdiffusive behavior in this regime with multiple dynamical time scales. Here we demonstrate that the waiting-time distribution of particle entrapments in clusters reflects these variations in the dynamics. Two- and many-body effects are cleanly delineated by computing these waiting times using a first passage time theory for excursions in the pair potential. For internally ordered clusters the accompanying slower time scale is found to be on the order of the escape time for a particle buried in a crystalline cluster.