Universal Quantum Physics in Driven Open Many-Body Systems
University of Cologne
Quantum optics and many-body physics increasingly merge together in ultracold atomic gases and certain classes of solid state systems. This gives rise to new non-equilibrium scenarios even in stationary state, where coherent and dissipative dynamics appear on an equal footing. Oftentimes however, in the transition from microscopic scales to macroscopic distances, much of the underlying quantum dynamics is washed out, and the long distance many-body physics is (semi-)classical.
Here we present two instances which do not follow this generic pattern. The first addresses the critical dynamics in a driven open system with a dark state realizable in microcavity arrays. We find it governed by a new non-equilibrium universality class, characterized by the absence of decoherence and thermalization. The second focuses on an ensemble of driven Rydberg atoms, in which the interplay of constrained coherent quantum dynamics and dissipation leads to a new variant of a non-equilibrium absorbing state transition beyond the classical paradigm of directed percolation.
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