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DY: Fachverband Dynamik und Statistische Physik
DY 31: Anomalous Diffusion
DY 31.2: Talk
Thursday, March 14, 2013, 15:15–15:30, H48
Subdiffusive exciton motion in systems with heavy-tailed disorder — •Sebastiaan M. Vlaming1,2,3, Alexander Eisfeld1, Victor A. Malyshev2, and Jasper Knoester2 — 1Max Planck Institute for Physics of Complex Systems, Dresden, Germany — 2University of Groningen, Groningen, The Netherlands — 3Massachusetts Institute of Technology, Cambridge, USA
The optical and excitation transport properties of many systems, such as molecular aggregates, photosynthetic complexes and organic photovoltaics, are determined by the collective properties of the relevant excitations, which are strongly influenced by interactions with their environment. In modeling the behavior of these collective excitations in a disordered environment, one conventionally often considers model parameters as stochastic quantities with Gaussian distributions. However, it has been suggested [1] that the limitation to Gaussian distributions is not necessarily the best choice, and novel effects such as exchange broadening and anomalous exciton localization have been shown to be possible when generalizing to the wider class of Lévy distributions. In this study, we investigate the excitation dynamics in such Lévy disordered systems, where we consider molecular aggregates as a model system. It is shown that the exciton dynamics changes qualitatively when generalizing to Lévy disorder distributions, leading to sub-diffusive (i.e. less mobile than diffusive) behavior of the exciton transport.
[1] AE, SMV, VAM, and JK, Phys. Rev. Lett. 105, 137402 (2010) [2] SMV, AE, VAM, and JK, to be submitted