Formation of Transient Clusters on Nanoscopic Length Scales in a Simulated One-Component Supercooled Liquid

Abstract

Dense liquids above their glass transition exhibit spatially heterogeneous dynamics in which regions within the liquid exhibit enhanced or diminished mobility relative to the average on some time scale. Substantial evidence suggests that these regions are confined to nanoscopic sizes at temperatures close to the mode coupling temperature T ^MCT, and reach well beyond the characteristic length scale over which the two-point static structure of the liquid is correlated. In this paper, we investigate the formation of clusters of mobile particles in a dynamically heterogeneous model liquid. We find that clusters are formed as a result of mobility propagation that begins from distributed locations confined within a nanoscopic local structure. This mobility is facilitated through the development of quasi-one dimensional string-like rearrangements within the nanoscopic region.

Keywords:

• Glass transition
• Computer simulation of liquid structure

Acknowledgements

We are grateful to the University of Michigan Center for Advanced Computing for generous access to the AMD Athlon cluster under the NPACI program.