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On polydispersity and the hard-sphere glass transition

2013/10/17 by Zaccarelli, Emanuela, Liddle, Siobhan M., Poon, Wilson C. K.
#FOS: Physical sciences #Soft Condensed Matter (cond-mat.soft)

paper · doi:10.48550/arxiv.1310.4876

Abstract

We simulate the dynamics of polydisperse hard spheres at high packing fractions, ϕ, with an experimentally-realistic particle size distribution (PSD) and other commonly-used PSDs such as gaussian or top hat. We find that the mode of kinetic arrest depends on the PSD's shape and not only on its variance. For the experimentally-realistic PSD, the largest particles undergo an ideal glass transition at ϕ∼ 0.588 while the smallest particles remain mobile. Such species-specific localisation was previously observed only in asymmetric binary mixtures. Our findings suggest that the recent observation of ergodic behavior up to ϕ∼ 0.6 in a hard-sphere system is not evidence for activated dynamics, but an effect of polydispersity.

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