Hannover 2010 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 21: Poster I
Q 21.56: Poster
Tuesday, March 9, 2010, 16:00–19:00, Lichthof
Analytic approximations of the Jaynes-Cummings-Hubbard model with application to ion chains — •Alexander Mering1, Michael Fleischhauer1, Peter A. Ivanov2, and Kilian Singer2 — 1Fachbereich Physik and research center OPTIMAS, Technische Universität Kaiserslautern — 2Institut für Quanteninformationsverarbeitung, Universität Ulm
We discuss analytic approximations to the ground-state phase diagram of the homogeneous Jaynes-Cummings-Hubbard (JCH) Hamiltonian with general short-range hopping. Specifically, we consider the cases of a linear array of coupled cavities and a linear ion chain describing radial phonon excitations of the ions coupled to an external laser field tuned to the red motional sideband with Coulomb-mediated hopping. We derive approximate analytic expressions for the boundaries between Mott-insulating and superfluid phases and give explicit expressions for the critical value of the hopping amplitude within the different approximation schemes together with a comparison to mean-field results. Additionally, in the case of an array of cavities which is represented by the standard JCH model, we compare both approximations to numerical data from density-matrix renormalization-group (DMRG) calculations.