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Description
Supercooled liquids exhibit spatial heterogeneity in the dynamics of their fluctuating atomic arrangements, with particle dynamics often dominated by stringlike motions where lines of particles perform activated hops cooperatively [1]. In glassy systems, a void takes the form of a quasivoid composed of a few neighboring free volumes and is transported through the stringlike motions it induces [2]. Similar quasivoid actions are also observed in fully glassy systems with a large polydispersity. In our study, we are investigating a three-dimensional polydisperse repulsive potential system using the Activation-Relaxation Technique nouveau(ARTn)[3], an algorithm that explores the potential energy landscape by converging from a local minimum energy configuration to nearby saddle-point configurations. We aim to collect thousands of saddle points to analyze the distribution of activation energies [4] and compare the positions of quasivoids identified by ARTn and iso-configuration methods. Additionally, we will compare the corresponding hopping rates calculated using iso-configuration with the results from ARTn.The eventual aim is to find the interactions between strings and build a transition state theory based on quasivoids.
[1] A. H. Marcus, J. Schofield, and S. A. Rice, Experimental observations of non-Gaussian behavior and stringlike cooperative dynamics in concentrated quasi-two-dimensional colloidal liquids, Phys. Rev. E 60, 5725 (1999).
[2] C. T. Yip, M. Isobe, C. H. Chan, S. Ren, K. P. Wong, Q. Huo, C.-S. Lee, Y.-H. Tsang, Y. Han, and C. H. Lam, Direct Evidence of Void-Induced Structural Relaxations in Colloidal Glass Formers, Phys. Rev. Lett. 125, 258001 (2020).
[3] N. Mousseau and G. Barkema, Traveling through potential energy landscapes of disordered materials: The activation-relaxation technique, Phys. Rev. E 57, 2419 (1998).
[4] S. Swayamjyoti, J. F. Löffler, and P. M. Derlet, Local structural excitations in model glasses, Phys. Rev. B 89, 224201 (2014).
