We propose a scheme for the deterministic coherent manipulation of two atomic qutrits, trapped in separate cavities coupled through a short optical fibre or optical resonator. We study such a system in the regime of dispersive atom-field interactions, where the dynamics of atoms, cavities and fibre operates through virtual population of both the atomic excited states and photonic states in the cavities and fibre. We show that the resulting effective dynamics allows for the creation of robust qutrit entanglement, and thoroughly investigate the influence of imperfections and dissipation, due to atomic spontaneous emission and photon leakage, on the entanglement of the two qutrits state.
We propose to engineer qutrit-qutrit entanglement through resonant atom-cavity interaction assisted by moderate laser driving, study two parameter regimes, respectively, of asymmetric atom-laser coupling and of asymmetric atom-cavity coupling, and find that both the coupling regimes possess the advantage of short operation time, compared with the previous ones achieved by dispersive interaction, adiabatic passage, and even quantum Zeno dynamics. We check numerically the influences of the parameter fluctuations and dissipation on the scheme and show it to be robust. The scheme can also be generalized to other physical systems such as the ion trap.
A scheme is proposed for the generation of a three-dimensional entangled state for two atoms trapped in a cavity via quantum Zeno dynamics. Because the scheme is based on the resonant interaction, the time required to produce entanglement is very short compared with the dispersive protocols. We show that the resulting effective dynamics allows for the creation of robust qutrit-qutrit entanglement. The influence of various decoherence processes such as spontaneous emission and photon loss on the fidelity of the entangled state is investigated. Numerical results show that the scheme is robust against the cavity decay since the evolution of the system is restricted to a subspace with null-excitation cavity fields. Furthermore, the present scheme has been generalized to realize
N-dimensional entanglement for two atoms.
We present a scheme for generating entangled states of two qutrits, by using a 4-level system and a 3-level system coupled to a single cavity. Because of only employing resonant interactions, the entangled state can be fast created. This scheme is easy to implement in experiments since only a single cavity is needed and none of measurement, auxiliary system and identical system-cavity coupling constant is required. Furthermore, two-qutrit partially or maximally entangled states can be created by using this scheme. The proposal is quite general, which can be used to prepare entangled states of two qutrits in various physical systems, such as two natural or artificial atoms of the Λ-type or Δ-type three lowest levels, coupled to an optical or microwave cavity.
We present a protocol that allows the generation of a maximally entangled state between individual atoms held in spatially separate cavities. Assuming perfect detectors and neglecting spontaneous emission from the atoms, the resulting idealized scheme is deterministic. Under more realistic conditions, when the atom-cavity interaction departs from the strong coupling regime, and considering imperfect detectors, we show that the scheme is robust against experimental inefficiencies and yields probabilistic entanglement of very high fidelity.
The generation of entanglement between two identical coupled cavities, each containing a single three-level atom, is studied when the cavities exchange two coherent photons and are in the
N=2,4 manifolds, where
N represents the maximum number of photons possible in either cavity. The atom-photon state of each cavity is described by a qutrit for
N=2 and a five-dimensional qudit for
N=4. However, the conservation of the total value of
N for the interacting two-cavity system limits the total number of states to only 4 states for
N=2 and 8 states for
N=4, rather than the usual 9 for two qutrits and 25 for two five-dimensional qudits. In the
N=2 manifold, two-qutrit states dynamically generate four maximally entangled Bell states from initially unentangled states. In the
N=4 manifold, two-qudit states dynamically generate maximally entangled states involving three or four states. The generation of these maximally entangled states occurs rather rapidly for large hopping strengths. The cavities function as a storage of periodically generated maximally entangled states.