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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.14: Poster

Donnerstag, 30. März 2006, 16:00–18:00, P1

Coherent exciton transport in dendrimers and continuous-time quantum walks — •Veronika Bierbaum, Oliver Mülken, and Alexander Blumen — Institute for Physics, University of Freiburg, Herrmann-Herder-Str. 3, 79104 Freiburg, Germany

We model coherent exciton transport in dendrimers by continuous-time quantum walks (CTQWs) [1]. Here only the topology of the dendrimer determines the dynamics. Depending on the initial excitation we find that the transport to certain nodes of the dendrimer is blocked and the long time average of the quantum mechanical transition probability between two nodes of the dendrimer shows characteristic patterns. Furthermore, for small dendrimers where the initial excitation is at the central node, the coherent transport shows perfect recurrence. For larger dendrimers, the recurrence is not perfect anymore. This resembles results for discrete quantum carpets [3]. When the initial excitation starts from the central node, the problem can be mapped onto a line which simplifies the computational effort. For the (space) average of the quantum mechanical probability to be still or again at the initial site, we obtain based on the Cauchy-Schwarz inequality a simple lower bound. ∖Zitat{1}{Oliver Mülken, Veronika Bierbaum, Alexander Blumen; in preparation} ∖Zitat{2}{Oliver Mülken, Alexander Blumen; Phys. Rev. E 71, 016101 (2005)} ∖Zitat{3}{Oliver Mülken, Alexander Blumen; Phys. Rev. E 72, 036128 (2005)}