An Isaac Newton Institute Workshop

Relaxation Dynamics of Macroscopic System

Activated aging dynamics and negative fluctuation-dissipation ratios

9th January 2006

Authors: Berthier, L (Universite Montpellier II), Garrahan, J (Nottingham), Leonard, S (), Mayer, P (), Sollich, P (King's College London)

Abstract

In glassy materials aging proceeds at large times via thermal activation. We show that this can lead to negative dynamic response functions and novel and well-defined violations of the fluctuation-dissipation theorem, in particular, negative fluctuation-dissipation ratios. Our analysis is based on detailed theoretical and numerical results for the activated aging regime of simple kinetically constrained models. Our results are relevant to a variety of physical situations such as aging in glass-formers, thermally activated domain growth and granular compaction.