Berlin 2012 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 4: Quantum Dynamics, Decoherence, and Quantum Information

DY 4.5: Talk

Monday, March 26, 2012, 16:00–16:15, MA 001

Dynamics in open systems - from assisted to impeded transport — Petrus Schijven, Alexander Blumen, and •Oliver Mülken — Institute of Physics, University of Freiburg, Germany

We study the dynamics of excitons in molecular aggregates, such as, e.g., photosynthetic complexes or J-aggregates. The dynamics will be modeled by the so-called quantum stochastic walk (QSW) which allows - on a phenomenological level - to interpolate between purely coherent (quantal) transport and purely incoherent (diffusive) transport. Here, the quantum system with a given Hamiltonian is coupled to an environment which we assume to induce diffusive behavior (derived from Fermis golden rule). By introducing excition sources and drains (traps) for the exciton, we show the importance of the initial preparation for, say, transport efficiency measures such as the expected survival time of the exciton [1]. For a given system, a suitable choice of the initial preparation allows to enhance or impede the transport.

[1] P. Schijven, A. Blumen, and O. Mülken, in preparation (2012)