Single-parameter aging in a binary Lennard-Jones system

This paper studies physical aging by computer simulations of a 2:1 Kob–Andersen binary Lennard-Jones mixture, a system that is less prone
to crystallization than the standard 4:1 composition. Starting from thermal-equilibrium states, the time evolution of the following four quantities
is monitored by following up and down jumps in temperature: potential energy, virial, average squared force, and the Laplacian of
the potential energy. Despite the fact that significantly larger temperature jumps are studied here than in typical similar experiments, to a
good approximation, all four quantities conform to the single-parameter-aging scenario derived and validated for small jumps in experiments
[T. Hecksher, N. B. Olsen, and J. C. Dyre, J. Chem. Phys. 142, 241103 (2015)]. As a further confirmation of single-parameter aging with a
common material time for the four different quantities monitored, their relaxing parts are found to be almost identical for all temperature
jumps.