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Quantum optical realizations of many-body systems must often be considered as open systems and thus offer a way to study quantum correlations and phase transitions in a non-equilibrium steady-state. The competition between interactions and fluctuations inherent to an open system will be discussed for the experimentally relevant examples of optically driven Rydberg gases and Rydberg polaritons. The steady-state phase transition to crystalline order in a lattice gases will be discussed as well as the dynamics of its build-up. In the second part photons coupled to Rydberg atoms under conditions of electromagnetically induced transparency will be considered. The coupling results in strongly interacting polaritons, which behave like hard-sphere objects with non-local interaction giving rise to a non-local nonlinear optics.

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M. Fleischhauer, Kaiserslautern
seminar room TP 0.03
Contact: not specified