Berlin 2014 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 15: Ultracold plasmas and Rydberg systems II (with A)
Q 15.1: Vortrag
Montag, 17. März 2014, 14:00–14:15, DO24 1.101
Critical slow down of a dissipative phase transition in a 2D Rydberg lattice gas — •Michael Höning1, Wildan Abdussalam2, Thomas Pohl2, and Michael Fleischhauer1 — 1Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany — 2Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
We study two dimensional lattice systems of atoms driven near resonance to strongly interacting Rydberg states. In general dipole blockade gives rise to strong short range correlations of excitations. Dynamical Monte-Carlo simulations of equivalent rate equation models show that for specific driving schemes a phase transition of the steady state to true long range order occurs. The phase diagram is however markedly different from mean-field predictions.
At the phase transition a discrete lattice symmetry is broken and it is found that the system undergoes a critical slow down. The dissipative gap of the system closes in the ordered phase, while in the paramagnetic region relaxation occurs on time scales of single site physics. This behavior is analogous to the formation and dynamics of domain walls in classical Ising models of magnetism. The stationary state of the driven lattice gas is nonetheless protected from local disturbances as they relax on short time scales.