Off equilibrium fluctuations in a polymer glass.

Lionel Buisson (1) , Sergio Ciliberto (1)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon

The fluctuation-dissipation relation (FDR) is measured on the dielectric properties of a polymer glass (polycarbonate). It is observed that the fluctuation dissipation theorem is strongly violated after a quench from above to below the glass transition temperature. The amplitude and the persistence time of this violation are decreasing functions of frequency. Around $1Hz$ it may persist for several hours. The origin of this violation is a highly intermittent dynamics characterized by large fluctuations and strongly non-Gaussian statistics. The intermittent dynamics depends on the quenching rate and it disappears after slow quenches. The relevance of these results for recent models of aging are discussed.

Keywords: aging; polymers; out of equilibrium dynamics; glass dynamics

Domains: Physics [physics]; Condensed Matter [cond-mat]; Materials Science [cond-mat.mtrl-sci]; Physics [physics]; Condensed Matter [cond-mat]; Statistical Mechanics [cond-mat.stat-mech]

Lionel Buisson, Sergio Ciliberto. Off equilibrium fluctuations in a polymer glass.. Physica D: Nonlinear Phenomena, 2005, 204 (1), pp.14. ⟨ensl-00180053⟩