Fluctuation-dissipation relations and energy landscape in an out-of-equilibrium strong glass-forming liquid

TL;DR

This paper investigates the out-of-equilibrium dynamics of a strong glass-forming liquid after a temperature jump, revealing that its effective temperature is unexpectedly lower than the bath temperature, contrasting with fragile liquids.

Contribution

It provides the first analysis of fluctuation-dissipation relations in a strong glass-former, highlighting a novel behavior of effective temperature during aging.

Findings

Effective temperature is lower than the bath temperature in the strong liquid.

Contrasts with the behavior observed in fragile liquids.

Offers insights into the energy landscape of strong glass-formers.

Abstract

We study the out-of-equilibrium dynamics following a temperature-jump in a model for a strong liquid, BKS-silica, and compare it with the well known case of fragile liquids. We calculate the fluctuation-dissipation relation, from which it is possible to estimate an effective temperature $T_{eff}$ associated to the slow out-of-equilibrium structural degrees of freedom. We find the striking and unexplained result that, differently from the fragile liquid cases, $T_{eff}$ is smaller than the bath temperature.