Scheme for the preparation of multiparticle entanglement in cavity QED

Abstract

Here we present a quantum electrodynamics (QED) model involving a large-detuned single-mode cavity field and n identical two-level atoms. One of its applications for the preparation of the multiparticle states is analyzed. In addition to the Greenberger-Horne-Zeilinger (GHZ) state, the W class states can also be generated in this scheme. The further analysis for the experiment of the model of n = 2 case is also presented by considering the possible three-atom collision.PACS ) was shown by Bell [3] to have stronger correlations than allowed by any local hidden variable theory. For the multi-particle entanglement states, there are many properties more peculiar than the two-party ones. For example, the Greenberger-HorneZeilinger (GHZ) state [4,5] Φ ABC = 1 √ 2 (|111 ± |000 ), a canonical three-particle entanglement state exhibits the contradiction between local hidden variable theories and quantum mechanics even for nonstatistical predictions, as opposed to the statistical ones for the EPR states. Many papers have discussed the multiparticle entanglement and its applications [6,7]. In the paper [8], the authors proved that there exists another kind of peculiar genuine tripartite entanglement W states W = 1 √ 3 (|001 + |010 + |100 ), which is inequivalent to the GHZ states in the sense that they cannot been converted to each other even under stochastic local operations and classical communication (SLOCC); that is, through LOCC but without imposing that it has to be achieved with certainty [9]. The GHZ state is maximally in several senses [10], for instance, it maximally violates Bell-type inequalities, the mutual information of measurement outcomes is maximal, it is maximally stable against (white) noise and one can locally obtain from a GHZ state with unit probability an EPR state shared between any two of the three parties. Another relevant feature is that when any one of the three qubits is traced out, the remaining two are in separable -and therefore unentangled -state. Thus, the entanglement properties of the GHZ state are very fragile under particle losses. Oppositely, the entanglement of the W state has the highest degree of endurance against loss of one of the three qubits which is argued as an important property in any situation where one of the three parties decide not to cooperate with the other two [8]. For the generalized form W n = 1 √ n |n − 1, 1 , where |n − 1, 1 denotes the totally symmetric state including n − 1 zeros and 1 ones, the concurrence (which is related to the formation entanglement) of any reduced density operators ρ k.u , C k,u (ρ k.u ) = 2/n, which indicates the maximal entanglement achievable for any reduced two parties of system in any pure state [8,11]. The states which can been converted to each other under SLOCC belong to the same class, then there are at least two inequivalent classes of multiparticle entanglement states: the GHZ state class and the W state class [8].Recently, it has been realized that quantum resources can be useful in information processing where quantum entang...

Teleportation of a two-particle entangled state via W class states

“…Now, the preparation of W state have been discussed in Ref. [17,18], so our scheme may be realized in experiment.…”

Effect of Cavity QED on Entanglement

“…Lets consider the effective Hamiltonian of the Jaynes Cumming model in its far-off resonant case [26,27] (δ g, and adiabatic elimination of the atomic coherence)…”

Pulse shaping by coupled cavities: Single photons and qudits

“…State transfer [1,2,3,4,5,6,7], two-qubit gates [8,9,10,11,12,13,14] and entanglement generation [1,9,10,11,15,16,17,18] can all be realized through controlled coupling of spatially distant atoms. This can be achieved by connecting the cavities in which atomic qubits reside via an optical fiber [1].…”