Berlin 2012 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 57: Complex Materials I

MM 57.3: Vortrag

Donnerstag, 29. März 2012, 16:15–16:30, H 1029

Quantum Diffusion in Metallic-Mean Labyrinth Tilings — •Stefanie Thiem and Michael Schreiber — Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz, Germany

We present results for the quantum diffusion in quasiperiodic tight-binding models in one, two, and three dimensions. The models are based on a class of one-dimensional quasiperiodic chains, in which the atoms are coupled by weak and strong bonds aligned according to the metallic-mean sequences. The associated labyrinth tilings in d dimensions are then constructed from the direct product of d such chains, which allows us to consider rather large systems numerically. The electronic transport properties are studied by computing the scaling behavior of the return probability and the mean square displacement of wave packets with respect to time. Our results reveal that the systems exhibit anomalous diffusion, where this behavior can be related to the underlying quasiperiodic structure by applying a renormalization group approach and perturbation theory.