Dynamical properties of a pinned glass former with increasing softness

S Suvarna and M Priya and PK Jaiswal, PHYSICS OF FLUIDS, 37, 073130 (2025).

DOI: 10.1063/5.0277764

The study of glass-forming systems with pinning has provided significant insight into the complex dynamics of glasses. Among various approaches, particle pinning has emerged as a powerful method to probe dynamical heterogeneity and slow relaxation in supercooled liquids. Although most studies focus on random pinning protocols, the impact of pinning in lower-dimensional systems remains underexplored. We investigate the dynamical properties of a two-dimensional binary Kob-Andersen glass interacting through a modified Mie (n,6) potential with varying repulsive ranges, using a template pinning protocol. For a fixed pinning concentration, our results on mean-squared displacements and self- diffusion coefficients indicate enhanced mobility of particles with an increase in softness of the repulsive core of the interaction potential. However, an increase in particle pinning hinders the particle mobility and amplifies the caging effect across these systems. Notably, the inverse temperature dependence of both the self-diffusion coefficient and the relaxation time for varying pinning concentrations collapses onto a universal curve when scaled by a characteristic temperature, defined as the temperature at which the self-diffusion coefficient approaches zero. At a fixed range of repulsive interaction, both the non-Gaussian parameter and the Stokes-Einstein violation increase with pinning concentration, indicating enhanced dynamic heterogeneity. However, at a fixed pinning fraction, these indicators show distinct trends with interaction range, reflecting the complex nature of dynamical heterogeneity. Our results offer insights into the role of concentration of pinned particles and the range of repulsive interactions in controlling the glass transition, with potential applications in designing disordered materials with desired transport properties.

Return to Publications page