Relaxation dynamics of simple glass-formers: The role of timescale separation and activated dynamics at the metabasin level.

G. A. APPIGNANESI; J. A. RODRIGUEZ FRIS; L. M. ALARCÓN; M. A. FRECHERO; R. A. MONTANI

Phisica Status Solidi (C)

Año: 2005 vol. 10 p. 3532 - 3535

1610-1634

Within the landscape approach the dynamical heterogeneities presented by model glasses at low temperatures have been shown to represent well-defined elemental activated events in the exploration of the potential energy surface, PES. This last picture relies on the validity of a timescale separation hypothesis: Transitions within basins of attraction or Inherent Structures, ISs, of the PES must be fast compared to transitions between ISs. Additionally, ISs might be grouped in metabasins, MBs, the transition between them involving infrequent large scale rearrangements. In this work we clearly demonstrate the MB superstructure of the PES and study the T dependence of the MB dynamics. We find that beyond certain T timescale separation begins to break down both at the IS and the MB levels, which implies the cessation of the prevalence of activated dynamics as the system loses complexity, diversity and glassiness.