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Quantum discord (Q

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posted on 19.08.2013, 00:00 by Raul Coto, Miguel Orszag

Figure 7. Quantum discord (Q), classical correlation (CC) and entanglement of formation (E) for the initial condition ρ(0); CC (red-dotted); Q (blue-dashed); E (solid); γ = 0.01; for the cavities 21'. Inset: a zoom of the quantum discord and classical correlation in the region λt: 2.4–3.8.


We study the propagation and distribution of quantum correlations through two chains of atoms inside cavities joined by optical fibres. This system is interesting because it can be used as a channel for quantum communication or as a network for quantum computation. In order to quantify those correlations, we used two different measurements: entanglement and quantum discord. We also use tangle for multipartite entanglement. We consider an effective Hamiltonian for the system and cavity losses, in the dressed atom picture, using the generalized master equation. We found a case where the quantum discord and the classical correlation are almost constant, and we also found multipartite entanglement, starting with only one excitation per chain. Finally, we propose a way to select the initial condition so that we can optimize the results for different purposes.