6533b854fe1ef96bd12ae965

RESEARCH PRODUCT

Dynamical Heterogeneities Below the Glass Transition

Walter KobKurt BinderKatharina Vollmayr-leeAnnette Zippelius

subject

PhysicsStatistical Mechanics (cond-mat.stat-mech)General Physics and AstronomyBinary numberFOS: Physical sciencesScale (descriptive set theory)Disordered Systems and Neural Networks (cond-mat.dis-nn)Condensed Matter - Disordered Systems and Neural NetworksCondensed Matter - Soft Condensed MatterKinetic energyMolecular physicsMolecular dynamicsAmplitudePosition (vector)ParticleSoft Condensed Matter (cond-mat.soft)Physical and Theoretical ChemistryGlass transitionCondensed Matter - Statistical Mechanics

description

We present molecular dynamics simulations of a binary Lennard-Jones mixture at temperatures below the kinetic glass transition. The ``mobility'' of a particle is characterized by the amplitude of its fluctuation around its average position. The 5% particles with the largest/smallest mean amplitude are thus defined as the relatively most mobile/immobile particles. We investigate for these 5% particles their spatial distribution and find them to be distributed very heterogeneously in that mobile as well as immobile particles form clusters. The reason for this dynamic heterogeneity is traced back to the fact that mobile/immobile particles are surrounded by fewer/more neighbors which form an effectively wider/narrower cage. The dependence of our results on the length of the simulation run indicates that individual particles have a characteristic mobility time scale, which can be approximated via the non-Gaussian parameter.

10.1063/1.1453962http://arxiv.org/abs/cond-mat/0109460