Local fluctuations in the ageing of a simple structural glass

Abstract

The presence of dynamical heterogeneities—that is, nanometre-scale regions of molecules rearranging cooperatively at very different rates compared with the bulk1,2—is increasingly being recognized as crucial to our understanding of the glass transition, from the non-exponential relaxation to the divergence of the relaxation times3. Although recent experiments4,5,6,7,8,9,10,11 and simulations12,13,14 have observed their presence directly, a clear physical picture of their origin is still lacking. Here, we present the first detailed characterization of the statistics of local fluctuations in a simulation of the ageing of a continuous-space, quasi-realistic structural glass model. A possible physical mechanism15,16,17,18 for the origin of dynamical heterogeneities in the non-equilibrium dynamics of glassy systems predicts universal scaling of the probability distributions of two-time local fluctuations. We find that to a first approximation this scaling is indeed satisfied by our results. We propose to test our results using confocal microscopy and atomic force microscopy experiments.

Cite this article

Castillo, H., Parsaeian, A. Local fluctuations in the ageing of a simple structural glass. Nature Phys 3, 26–28 (2007). https://doi.org/10.1038/nphys482

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