From Subaging to Hyperaging in Structural Glasses

• Published in: Physical review letters Vol. 129; no. 23; p. 238003
• Main Authors: Elizondo-Aguilera, Luis F, Rizzo, Tommaso, Voigtmann, Thomas
• Format: Journal Article
• Language: English
• Published: United States 02.12.2022
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.129.238003

We demonstrate nonequilibrium scaling laws for the aging and equilibration dynamics in glass formers that emerge from combining a relaxation equation for the static structure with the equilibrium scaling laws of glassy dynamics. Different scaling regimes are predicted for the evolution of the structural relaxation time τ with age (waiting time t_{w}), depending on the depth of the quench from the liquid into the glass: "simple" aging (τ∼t_{w}) applies for quenches close to the critical point of mode-coupling theory (MCT) and implies "subaging" (τ≈t_{w}^{δ} with δ<1) as a broad equilibration crossover for quenches to nearly arrested equilibrium states; "hyperaging" (or superaging, τ∼t_{w}^{δ^{'}} with δ^{'}>1) emerges for quenches deep into the glass. The latter is cut off by non-mean-field fluctuations that we account for within a recent extension of MCT, the stochastic β-relaxation theory (SBR). We exemplify the scaling laws with a schematic model that quantitatively fits simulation data.