Dresden 2006 – wissenschaftliches Programm

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DF: Dielektrische Festkörper

DF 5: Glass I (together with division ‘Dynamics and Statistical Physics’ [DY])

DF 5.6: Vortrag

Dienstag, 28. März 2006, 11:30–11:50, M{\"U}L Elch

Collective Single Particle Jumps Below The Glass Transition — •Katharina Vollmayr-Lee — Institut für Theoretische Physik, Universität Göttingen,Friedrich-Hund-Platz 1, D-37077 Göttingen,Germany

We study a binary Lennard-Jones mixture below the glass transition via molecular dynamics simulations. To investigate the dynamics of the system we define single particle jumps via their single particle trajectories. To study how the single particle jumps are correlated in time and space we investigate (I) clusters of simultaneously jumping particles and (II) temporally extended clusters, i.e. clusters of jump events for which the jumping particles are spatially nearby and the jumps occur at consecutive times. We find highly collective jump processes. The distribution of cluster sizes P(s) is independent of temperature and follows a power law P(s) ∼ s^−τ with τ ≈ 2.7 in case (I) and τ ≈ 2.2 in case (II). By studying the average coordination number within the clusters as a function of the cluster size, we find that the shape of the clusters is string-like.

We thank K. Binder, A. Zippelius, J. Horbach, and B. Vollmayr-Lee, and we gratefully acknowledge financial support from SFB 262 and DFG Grant No. Zi 209/6-1.