Projects per year
Abstract
We discuss the Jaynes–Cummings–Hubbard model describing the superfluid–Mott insulator transition of polaritons (i.e., dressed photon–qubit states) in coupled qubit–cavity arrays in the crossover from strong to weak correlations. In the strongly correlated regime the phase diagram and the elementary excitations of lattice polaritons near the Mott lobes are calculated analytically using a slaveboson theory (SBT). The opposite regime of weakly interacting polariton superfluids is described by a weakcoupling meanfield theory for a generalized multimode Dicke model. We show that a remarkable relation between the two theories exists in the limit of large photon bandwidth and large negative detuning, i.e., when the nature of polariton quasiparticles becomes qubitlike. In this regime, the weakcoupling theory predicts the existence of a single Mott lobe with a change of the universality class of the phase transition at the tip of the lobe, in perfect agreement with the SBT. Moreover, the spectra of low energy excitations, i.e., the sound velocity of the Goldstone mode and the gap of the amplitude mode match exactly as calculated from both theories.
Original language  English 

Pages (fromto)  224020 
Number of pages  1 
Journal  Journal of Physics B: Atomic, Molecular and Optical Physics 
Volume  46 
Issue number  22 
DOIs  
Publication status  Published  1 Nov 2013 
Fingerprint
Dive into the research topics of 'From the Jaynes–Cummings–Hubbard to the Dicke model'. Together they form a unique fingerprint.Projects
 2 Finished

Topological Protection and NonEquilibriu: Topological Protection and NonEquilibrium States in Strongly Correlated Electron Systems
Wahl, P., Baumberger, F., Davis, J. C., Green, A., Hooley, C., Keeling, J. M. J. & Mackenzie, A.
1/09/11 → 31/08/17
Project: Standard

Macroscopic quantum coherence: Macroscopic quantum coherence in nonequilibrium and driven quantum systems
1/09/10 → 31/03/14
Project: Fellowship