125 research outputs found
Polaritonic properties of the Jaynes-Cummings lattice model in two dimensions
Light-matter systems allow to realize a strongly correlated phase where
photons are present. In these systems strong correlations are achieved by
optical nonlinearities, which appear due to the coupling of photons to
atomic-like structures. This leads to intriguing effects, such as the quantum
phase transition from the Mott to the superfluid phase. Here, we address the
two-dimensional Jaynes-Cummings lattice model. We evaluate the boundary of the
quantum phase transition and study polaritonic properties. In order to be able
to characterize polaritons, we investigate the spectral properties of both
photons as well as two-level excitations. Based on this information we
introduce polariton quasiparticles as appropriate wavevector, band index, and
filling dependent superpositions of photons and two-level excitations. Finally,
we analyze the contributions of the individual constituents to the polariton
quasiparticles.Comment: 5 pages, 4 figures, Proceedings of the Conference on Computational
Physics CCP, June 2010, Trondheim, Norwa
Quantum Many-Body Phenomena in Coupled Cavity Arrays
The increasing level of experimental control over atomic and optical systems
gained in the past years have paved the way for the exploration of new physical
regimes in quantum optics and atomic physics, characterised by the appearance
of quantum many-body phenomena, originally encountered only in condensed-matter
physics, and the possibility of experimentally accessing them in a more
controlled manner. In this review article we survey recent theoretical studies
concerning the use of cavity quantum electrodynamics to create quantum
many-body systems. Based on recent experimental progress in the fabrication of
arrays of interacting micro-cavities and on their coupling to atomic-like
structures in several different physical architectures, we review proposals on
the realisation of paradigmatic many-body models in such systems, such as the
Bose-Hubbard and the anisotropic Heisenberg models. Such arrays of coupled
cavities offer interesting properties as simulators of quantum many-body
physics, including the full addressability of individual sites and the
accessibility of inhomogeneous models.Comment: overview article, 27 pages, 31 figure
Nonequilibrium phases in hybrid arrays with flux qubits and NV centers
We propose a startling hybrid quantum architecture for simulating a
localization-delocalization transition. The concept is based on an array of
superconducting flux qubits which are coupled to a diamond crystal containing
nitrogen-vacancy (NV) centers. The underlying description is a
Jaynes-Cummings-lattice in the strong-coupling regime. However, in contrast to
well-studied coupled cavity arrays the interaction between lattice sites is
mediated here by the qubit rather than by the oscillator degrees of freedom.
Nevertheless, we point out that a transition between a localized and a
delocalized phase occurs in this system as well. We demonstrate the possibility
of monitoring this transition in a non-equilibrium scenario, including
decoherence effects. The proposed scheme allows the monitoring of
localization-delocalization transitions in Jaynes-Cummings-lattices by use of
currently available experimental technology. Contrary to cavity-coupled
lattices, our proposed recourse to stylized qubit networks facilitates (i) to
investigate localization-delocalization transitions in arbitrary dimensions and
(ii) to tune the inter-site coupling in-situ.Comment: Version to be published in Phys. Rev.
Quantum Simulation with Interacting Photons
Enhancing optical nonlinearities so that they become appreciable on the
single photon level and lead to nonclassical light fields has been a central
objective in quantum optics for many years. After this has been achieved in
individual micro-cavities representing an effectively zero-dimensional volume,
this line of research has shifted its focus towards engineering devices where
such strong optical nonlinearities simultaneously occur in extended volumes of
multiple nodes of a network. Recent technological progress in several
experimental platforms now opens the possibility to employ the systems of
strongly interacting photons these give rise to as quantum simulators. Here we
review the recent development and current status of this research direction for
theory and experiment. Addressing both, optical photons interacting with atoms
and microwave photons in networks of superconducting circuits, we focus on
analogue quantum simulations in scenarios where effective photon-photon
interactions exceed dissipative processes in the considered platforms.Comment: invited review for Journal of Optic
Quantum Many-Body Phenomena in Coupled Cavity Arrays
The increasing level of experimental control over atomic and optical systems gained in the past years have paved the way for the exploration of new physical regimes in quantum optics and atomic physics, characterised by the appearance of quantum many-body phenomena, originally encountered only in condensed-matter physics, and the possibility of experimentally accessing them in a more controlled manner. In this review article we survey recent theoretical studies concerning the use of cavity quantum electrodynamics to create quantum many-body systems. Based on recent experimental progress in the fabrication of arrays of interacting micro-cavities and on their coupling to atomic-like structures in several different physical architectures, we review proposals on the realisation of paradigmatic many-body models in such systems, such as the Bose-Hubbard and the anisotropic Heisenberg models. Such arrays of coupled cavities offer interesting properties as simulators of quantum many-body physics, including the full addressability of individual sites and the accessibility of inhomogeneous models
Supersolid and pair correlations of the extended Jaynes-Cummings-Hubbard model on triangular lattices
We study the extended Jaynes-Cummings-Hubbard model on triangular cavity
lattices and zigzag ladders. By using density-matrix renormalization group
methods, we observe various types of solids with different density patterns and
find evidence for light supersolids, which exist in extended regions of the
phase diagram of the zigzag ladder. Furthermore, we observe strong pair
correlations in the supersolid phase due to the interplay between the atoms in
the cavities and atom-photon interaction. By means of cluster mean-field
simulations and a scaling of the cluster size extending our analysis to
two-dimensional triangular lattices, we present evidence for the emergence of a
light supersolid in this case also.Comment: 11 pages, 16 figure
Excitation spectra of strongly correlated lattice bosons and polaritons
Spectral properties of the Bose-Hubbard model and a recently proposed
coupled-cavity model are studied by means of quantum Monte Carlo simulations in
one dimension. Both models exhibit a quantum phase transition from a Mott
insulator to a superfluid phase. The dynamic structure factor and
the single-particle spectrum are calculated, focusing on the
parameter region around the phase transition from the Mott insulator with
density one to the superfluid phase, where correlations are important. The
strongly interacting nature of the superfluid phase manifests itself in terms
of additional gapped modes in the spectra. Comparison is made to recent
analytical work on the Bose-Hubbard model. Despite some subtle differences due
to the polaritonic particles in the cavity model, the gross features are found
to be very similar to the Bose-Hubbard case. For the polariton model, emergent
particle-hole symmetry near the Mott lobe tip is demonstrated, and temperature
and detuning effects are analyzed. A scaling analysis for the generic
transition suggests mean field exponents, in accordance with field theory
results.Comment: 14 pages, 14 figures, final versio
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