Berlin 2008 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 20: POSTERS Driven Soft Matter

CPP 20.29: Poster

Mittwoch, 27. Februar 2008, 16:00–18:30, Poster A

Non-affine deformations of inherent structure as signature of cooperativity in supercooled liquids — •Emanuela Del Gado, Patrick Ilg, Martin Kroeger, and Hans Christian Oettinger — Polymer Physics, ETH Zürich

Experimental and theoretical investigations close to the glass transition indicate the presence of cooperatively rearranging regions of growing size, but it is still debated whether and how cooperativity can be related to structural changes. We search for a signature of the onset of cooperative dynamics in the structural features of supercooled liquids from a novel perspective [1]. We unveil the existence of non-affinely rearranging regions in the inherent structures (IS) by numerical simulations of model glass formers subject to static affine deformations combined with local energy minimizations [2]. In the liquid state IS, we find a broad distribution of rather large, non-affine displacements which are correlated only over small distances. At low temperatures, the onset of the cooperative dynamics corresponds to much smaller non-affine displacements correlated over larger distances. This indicates the presence of non-affinely rearranging domains of relevant size in the IS, which can be seen as the IS counterpart of the cooperatively rearranging regions in the dynamics. This idea suggests a new insight into possible structural signatures of slow cooperative dynamics of supercooled liquids and supports the connections with elastic heterogeneities found in amorphous solids.

[1] H. C. Oettinger, Phys. Rev. E 74, 011113 (2006). [2] E. Del Gado, P. Ilg, M. Kroeger and H.C. Oettinger, cond-mat/0711.1581.