Dynamical heterogeneities in hard-sphere systems near random close packing

ORAL

Abstract

Hard-sphere systems at finite temperatures diffuse at low packing fraction, but display glassy dynamics as the packing fraction increases toward random close packing (RCP). As the system approaches RCP, structural relaxation dramatically slows down and becomes highly cooperative and heterogeneous in space and time. We quantify dynamical heterogeneities in bidisperse hard-sphere systems as a function of packing fraction near RCP using the non-Gaussian parameter $\alpha_2$ and four-point density correlation function. We show that $\alpha_2$ does not diverge, but instead reaches an upper bound $< 2$ as the packing fraction approaches RCP. We present a simple theoretical model to explain this upper limit.

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Authors

  • W. Wendell Smith

    • Yale University

  • Peter Williams

    • Yale University

  • Mark Shattuck

    • The City College of New York
    • Benjamin Levich Institute and Physics Department, The City College of New York, New York, NY, USA
    • City College of New York

  • Corey O&#039;Hern

    • Yale University
    • Department of Physics, Department of Computational Biology and Bioinformatics, Yale University, New Haven, CT, USA