Single-parameter aging in a binary Lennard-Jones system

This paper studies physical aging by computer simulations of the non-standard 2:1 composition Kob-Andersen binary Lennard-Jones mixture, a system that is less prone to crystallization than the standard 4:1 mixture. The time evolution of the following four quantities is monitored following up and down jumps in temperature starting from states of thermal equilibrium: the potential energy, the virial, the average force magnitude squared, and the Laplacian of the potential energy. Despite the fact that significantly larger temperature jumps are studied here than in previous experiments, all four quantities conform to the approximate single-parameter aging scenario derived and validated for small jumps in experiments [Hecksher et al., J. Chem. Phys. 142, 241103 (2015)]. As a further confirmation of single-parameter aging, the relaxing parts of the four quantities studied are almost identical for all temperature jumps studied.