Hannover 2010 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 19: Ultra-Cold Plasmas and Rydberg System

A 19.3: Vortrag

Donnerstag, 11. März 2010, 11:15–11:30, B 302

Quantum excitation transport in flexible atomic aggregates — •Sebastian Wüster, Cenap Ates, Alexander Eisfeld, and Jan-Michael Rost — Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzer Strasse 38, 01187 Dresden

Transfer of electronic excitations on chains of atoms or molecules is important in many areas of physics, such as photosynthetic light-harvesting [1] or assemblies of Rydberg atoms in optical lattices. The electromagnetic interactions responsible for excitation propagation also exert mechanical forces on the chain, inducing motion of the constituents [2]. In such a flexible aggregate, the atomic motion is typically entangled with the state of the electronic excitation.

We consider a linear and a circular arrangement of Rydberg atoms on which a single excitation propagates via dipole-dipole transitions. In the circular scenario, a conical intersection between two Born-Oppenheimer surfaces of the chain’s electronic state has a dominating effect on the quantum dynamics. It strongly affects the atomic centre-of-mass motion and thereby decoheres the reduced electronic density matrix. For our investigation we employ both, full quantum mechanical calculations and a mixed quantum-classical surface-hopping method.

[1] R. van Grondelle and V.I. Novoderezhkin, Phys. Chem. Chem. Phys. 8, (2006) 793.

[2] C. Ates, A. Eisfeld and J.M. Rost, New J. Phys. 10 (2008) 045030.