Based on Lewis---Riesenfeld invariants and quantum Zeno dynamics, we propose an effective scheme for generating atomic NOON states via shortcuts to adiabatic passage. The photon losses are efficiently suppressed by engineering shortcuts to adiabatic passage in the scheme. The numerical simulation shows that the atomic NOON states can be generated with high fidelity.

Generation of atomic NOON states via shortcuts to adiabatic passage

We propose a scheme for generating atomic NOON states via adiabatic passage. In the scheme, a double $$\Lambda $$?-type three-level atom is trapped in a bimodal cavity, and two sets of $$\Lambda $$?-type three-level atoms are translated into and outside of two single-mode cavities, respectively. The three cavities connected by optical fibers are always in vacuum states. After a series of operations and suitable interaction time, we can obtain arbitrary large-$$n$$n NOON states of two sets of $$\Lambda $$?-type three-level atoms in distant cavities by performing a single projective measurement on the double $$\Lambda $$?-type three-level atom. Our scheme is robust against the spontaneous emissions of atoms, the decays of fibers, and photon leakage of cavities, due to the adiabatic elimination of atomic excited states and the application of adiabatic passage.

Generation of atomic NOON states via adiabatic passage

We propose a scheme for generating atomic NOON states via adiabatic passage. In the scheme, a double $\Lambda$-type three-level atom is trapped in a bimodal cavity and two sets of $\Lambda$-type three-level atoms are translated into and outside of two single mode cavities respectively. The three cavities connected by optical fibres are always in vacuum states. After a series of operations and suitable interaction time, we can obtain arbitrary large-$n$ NOON states of two sets of $\Lambda$-type three-level atoms in distant cavities by performing a single projective measurement on the double $\Lambda$-type three-level atom. Due to adiabatic elimination of atomic excited states and the application of adiabatic passage, our scheme is robust against the spontaneous emissions of atoms, the decays of fibres and cavities photon leakage. So the scheme has a high fidelity and feasibility under the current available techniques.

We present a scheme of choosing a dressed state as an evolutive path to prepare three-superconducting qubit (SQ) W state. In the circuit quantum electrodynamics, there are three SQs trapped, respectively, in three coplanar waveguide resonators, which are coupled to a superconducting coupler qubit. With the help of quantum Zeno dynamics, we get the effective Hamiltonian of the system. Our strategy is adding two auxiliary pulses to the effective Hamiltonian. New driving pulses can cancel non-adiabatic transitions, so the whole system will evolve exactly along the chosen path. By setting boundary conditions, the W state can be obtained in a short time. Furthermore, in the chosen evolutive path state, the intermediate state’s population can be restricted by setting appropriate parameters, which is very useful for resisting the effects of dissipation. Numerical simulations indicate that the proposed scheme is robust against spontaneous emissions, dephasing, the cavity photon leakage and the parameter fluctuations.

Fast preparing W state via a chosen path shortcut in circuit QED

We have shown that the application of modulating the secondary lattice is an efficient route to suppressing the generation of chaotic traveling waves of a Bose–Einstein Condensate with attractive interatomic interaction loaded into a moving optical superlattice consisting of two lattices. With the Melnikov method, we obtain the optimal value of the relative phase between the two lattice harmonics for the control of chaos. We also find that the regularization route as the potential depth of the secondary lattice is varied and fairly rich, including the period-doubling bifurcations.

Suppression of Chaos in a Bose–Einstein Condensate Loaded into a Moving Optical Superlattice Potential

We propose two schemes for generating Greenberger-Horne-Zeilinger and W states of three distant atoms In the present schemes, the atoms are individually trapped in three spatially separated optical cavities coupled by two optical fibres Performing an adiabatic passage along dark states, the population of cavities and fibres excited is negligible under certain conditions In addition, the spontaneous decay of atoms is also efficiently suppressed based on our proposals Furthermore, the discussion about the entanglement fidelity is given and we point out that our schemes work robustly with small fluctuations of experimental parameters

Deterministic generation of Greenberger{Horne{ Zeilinger and W states for three distant atoms via adiabatic passage ⁄

We propose a new scheme to achieve the tripartite entanglement based on the standard criteria [Phys. Rev. A 67 (2003) 052315] in a inverse-tripod atomic system. In our scheme, the atomic coherence is introduced by two microwave fields which drive the upper three levels of atom. By numerically simulating the dynamics of system, we investigate the generation and evolution of entanglement in the presence of atom and cavity decay. As a result, the present research provides an efficient approach to achieve fully tripartite entanglement with different frequencies and initial states for each entangled mode, which may have impact on the progress of multicolored multi-notes quantum information networks.

Lü Xin-You

Papers

Deterministic generation of Greenberger{Horne{ Zeilinger and W states for three distant atoms via adiabatic passage ⁄

Tripartite Entanglement via Microwave Driven Atomic Coherence