Quantum phase transition, spectral signatures and polaritonic properties of coupled cavity arrays
Michael Knap
Institute of Theoretical and Computational Physics, Graz University of Technology
15:00 - 16:00 Tuesday 18 May 2010 KFU Graz, Hoersaal 05.12

The enormous progress in controlling quantum optical and atomic systems has prompted ideas for new experimental realizations of strongly-correlated many body systems operating with light. These systems consist of photons confined in optical cavities, which interact strongly with atoms or atomiclike structures, see Figure. Due to the interaction between the two particle species optical nonlinearities appear, leading to a quantum phase transition from Mott to superfluid phase where photons are present! Exhibiting these intriguing properties light-matter systems might be used as quantum simulators for other strongly-correlated many body systems, such as the Bose-Hubbard model or might find their applications in quantum information processing.

In this talk the Jaynes-Cummings lattice model will be addressed, which describes a light-matter system containing a single atomiclike structure in each cavity. In particular, we discuss spectral properties of photons and atomic excitations. This allows us to characterize the polaritons, which are the elementary excitations of the Jaynes-Cummings lattice model. Our results demonstrate how the fundamental excitations of the Jaynes-Cummings lattice model are composed and provide thus valuable insight into the physics of light-matter systems.