We study a composite multimode light-two-level atom system in a cavity. We show that coupling of the two-level atom to multiple modes of the light destroys the Mott phase of the composite system thus making the system less useful platform for developing concepts in quantum information processing.
We investigate the entanglement dynamics in a quantum system consisting of three two-level atoms resonantly coupled to a single mode cavity in the presence of phase decoherence. With the help of the dynamical algebraic method, we obtain an analytical solution of the present system. The influence of phase decoherence on the entanglement of the system is studied. We find that the entanglement between the cavity field and any atom will be destroyed completely by phase decoherence as the system evolves. However, there is long-lived entanglement (or stationary state entanglement) of arbitrary two atoms, that is, the entanglement of atoms is more robust against phase decoherence than that of the atom-field system.
We study the one-excitation dynamics of a coupled cavity system composed of three cavities, each containing a two-level atom. By adjusting the atom–cavity detuning Δ, cavity–cavity hopping rate v and the initial atomic excitation residential, a wide variety of time-evolution behaviors can be realized. Under certain conditions, the two-atom maximally entangled states and three-atom W states can be obtained. The results provide a theoretical basis for the manipulation of quantum states in such a system and will contribute to the understanding of more complex systems.
Abstract We investigate a hybrid quantum system consisting of two coupled optical cavities, each containing an ensemble of coherently pumped artificial or real two-level atoms. The system is modelled within the dressed-state formalism, accounting for coherent driving and dissipative interactions with independent electromagnetic reservoirs. Focusing on the regime where the Rabi frequency greatly exceeds the collective spontaneous emission and cavity decay rates, respectively, we derive the equations of motion characterizing the system and analyse its steady-state behaviours. Special attention is given to the scenario in which only one cavity contains a pumped multi-atom ensemble, and as a consequence, coherent excitation transfer to the second cavity occurs via cavity–cavity coupling. In this case, the mean photon number in the second cavity mode scales proportional to the squared number of atoms, i.e., N2 from the first cavity. The proposed model offers insight into light–matter interaction in composite systems and suggests viable mechanisms for engineering collective interactions and non-local excitation transport in quantum optical platforms.
We study an atom-cavity system in which the cavity has several degenerate transverse modes. Mode-resolved cavity transmission spectroscopy reveals well-resolved atom-cavity resonances for several cavity modes, a signature of collective strong coupling for the different modes. Furthermore, the experiment shows that the cavity modes are coupled via the atomic ensemble contained in the cavity. The experimental observations are supported by a detailed theoretical analysis. The work paves the way to the use of interacting degenerate modes in cavity-based quantum information processing, where qubits corresponding to different cavity modes interact via an atom shared by the two modes. Our results are also relevant to the experimental realization of quantum spin glasses with ultracold atoms.