Aging in glasses: generalized Langevin equations and scaling laws

Thomas Voigtmann (DLR, Köln)

Jun 24. 2021, 15:30 — 16:00

Glasses are out-of-equilibrium materials and thus prone to aging effects: produced by a rapid quench in thermodynamic control parameter(s), the dynamics of the system is characterized by a (structural) relaxation time τ that grows with increasing waiting time tw after the quench.

I will present a recent theory to describe this aging dynamics on the basis of microscopic approaches leading to self-consistent generalized Langevin equations (SCGLE) for the non-stationary state. In the vicinity of the glass transition, scaling laws arise that predict regimes of "normal"; aging, τ~tw, "sub-aging", τ~tw^μ with μ<1, and "hyper-aging", τ~tw^μ' with μ'>1. The predictions are exemplified by adapting a schematic closure for the memory kernel akin to the mode-coupling theory (MCT), compared to molecular-dynamics simulation results; and finally, the role of non-mean-field type corrections to MCT in determining the waiting-time dependence is discussed.

Further Information
Venue:
ESI Boltzmann Lecture Hall
Recordings:
Recording
Associated Event:
Memory Effects in Dynamical Processes: Theory and Computational Implementation (Online Workshop)
Organizer(s):
Christoph Dellago (U of Vienna)
Anja Kuhnhold (U of Freiburg)
Hugues Meyer (U of Saarland)
Tanja Schilling (U of Freiburg)