Sommaire:

I would like to report my recent research regarding dynamic heterogeneities employing multi-point and multi-time correlations. My presentation will consist of two parts. (a) A three-point correlation function is calculated following the recent inhomogeneous mode-coupling theory (IMCT). We utilize a non-equilibrium molecular dynamics simulation, where the system is perturbed by the external potential coupled with the spontaneous density field. The three-point correlation is evaluated as the response of the two-point correlation due to the external field. Various scaling properties regarding the extracted length are investigated in comparison with the IMCT. (b) A multi-time extension of the usual four-point correlation is introduced to reveal the characteristic time scales of dynamic heterogeneities in glass-forming liquids. Molecular dynamics simulations are carried out for various models such as Kob-Andersen, Wahnstrom, soft-sphere, and Coslovich-Pastore network-forming liquids. From the comprehensive numerical calculations of the three-time correlation function, the temporal structures of the dynamic heterogeneities are characterized. We determine the associated lifetimes of above models and examine its role in the fragility.

Pour plus d'informations, merci de contacter Berthier L.