Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
DY: Fachverband Dynamik und Statistische Physik
DY 10: Posters I
DY 10.26: Poster
Montag, 14. März 2011, 17:00–19:00, P4
Are superdiffusive jumps in molecular diffusion triggered or destroyed by the chaotic dynamics of the molecule's internal degrees of freedom? — •Sarah Hallerberg1 and Astrid S. de Wijn2 — 1Chemnitz University of Technology — 2Radboud University Nijmegen
Long jumps in surface diffusion of organic molecules and nanoscale clusters have been observed experimentally, and were also found in numerical simulations. Recent studies[1] highlight the existence of a relation between the diffusion of molecules and the dynamics of their internal degrees of freedom. These internal chaotic dynamics lead to normal diffusion, even in the absence of thermal noise. Our contribution aims at determining the physical mechanism which trigger long superdiffusive jumps. Benzene on graphite is a prototype system and serves us to investigate these long jumps by postprocessing the output of atomistic simulations[1]. In more detail, we search for precursors[2] in the internal degrees of freedom by considering the energy in the vibrational modes of the linearised system and show that relevant precursors appear particularly in the torsional vibrations. Our results suggest a strong connection between lack of torsion of the molecule and long superdiffusive jumps.
[1] A. S. de Wijn and A. Fasolino. Journal of Physics: Condensed Matter, 21:264002, 2009. [2] S. Hallerberg, E. G. Altmann, D. Holstein, H. Kantz, Phys Rev. E, 2007, 75, 016706.