Mainz 2017 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 31: Poster Session III
A 31.29: Poster
Donnerstag, 9. März 2017, 17:00–19:00, P OG1
Rydberg superatom dynamics in optical lattices — •Fabian Letscher1,2, David Petrosyan3, and Michael Fleischhauer1 — 1Department of Physics and research center OPTIMAS, University of Kaiserslautern, Germany — 2Graduate School Materials Science in Mainz, Gottlieb-Daimler-Strasse 47, 67663 Kaiserslautern, Germany — 3Institute of Electronic Structure and Laser, FORTH, GR-71110 Heraklion, Crete, Greece
The strong and long-range interactions between Rydberg atoms can suppress more than one optical excitation within a certain blockade volume. A mesoscopic ensemble of atoms then forms a so-called Rydberg superatom. In contrast to a two-level system, strong dephasing during laser excitation of the superatom can lead to its Rydberg excitation probability approaching unity. A lattice of such strongly driven superatoms allow for simulations and studies of various phases and phase transitions of open many-body systems.
Here, we discuss the excitation dynamics and steady-state phases of Rydberg superatom lattices in two regimes of laser excitation, namely: the resonant (blockade) regime and off-resonant (facilitation) regime. In the blockade regime, we show that the systems in the steady state can form a bistable, antiferromagnetically ordered phase with long-range spatial correlations. In the facilitation regime, an excitation cascade may occur leading to a fast growth of Rydberg excitation clusters. We simulate the excitation dynamics on a triangular lattice reminiscent of frustrated spin models in a strongly dissipative environment and study the cluster collisions and the role of resulting defects.