Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1310.7776 · International Journal of Quantum Information

QUANTUM CORRELATIONS DYNAMICS OF QUASI-BELL CAT STATES

Mohammed Daoud A, R. Ahl Laamara, R. Essaber

Published Sep 1, 2013• 6 citations
arXivHTMLPDF

Abstract

A model of dynamics of quantum correlations of two modes quasi-Bell cat states, based on Glauber coherent states, is considered. The analytic expressions of pairwise entanglement of formation, quantum discord and its geometrized variant are explicitly derived. We analyze the distribution of quantum correlations between the two modes and the environment. We show that, in contrast with squared concurrence, entanglement of formation, quantum discord and geometric quantum discord do not follow the property of monogamy except in some particular situations that we discuss.

DOI
10.1142/s0219749913500573

Related papers

Quantum discord of Bell cat-states under amplitude damping

Mohammed Daoud A, R. Ahl Laamarab

The evolution of pairwise quantum correlations of Bell cat-states under amplitude damping is examined using the concept of quantum discord which goes beyond entanglement. A closed expression of the quantum discord is explicitly derived. We used of the Koashi-Winter relation. A relation which facilitates the optimization process of the conditional entropy. We also discuss the temporal evolution of bipartite quantum correlations under a dephasing channel and compare the behaviors of quantum discord and entanglement whose properties are characterized through the concurrence.

•Aug 17, 2016•12 citations

Quantum discord of Bell cat states under amplitude damping

Mohammed Daoud A, R. Ahl Laamara

The evolution of pairwise quantum correlations of Bell cat states under amplitude damping is examined using the concept of quantum discord which goes beyond entanglement. A closed expression of the quantum discord is explicitly derived. We used the Koashi–Winter relation, a relation which facilitates the optimization process of the conditional entropy. We also discuss the temporal evolution of bipartite quantum correlations under a dephasing channel and compare the behaviors of quantum discord and entanglement whose properties are characterized through the concurrence.

arXiv:1210.8309•Journal of Physics A Mathematical and Theoretical•Jul 24, 2012•15 citations

Monogamy properties of quantum and classical correlations

Gian Luca Giorgi

In contrast with entanglement, as measured by concurrence, in general, quantum discord does not possess the property of monogamy; that is, there is no tradeoff between the quantum discord shared by a pair of subsystems and the quantum discord that both of them can share with a third party. Here, we show that, as far as monogamy is considered, quantum discord of pure states is equivalent to the entanglement of formation. This result allows one to analytically prove that none of the pure three-qubit states belonging to the subclass of $W$ states is monogamous. A suitable physical interpretation of the meaning of the correlation information as a quantifier of monogamy for the total information is also given. Finally, we prove that, for rank 2 two-qubit states, discord and classical correlations are bounded from above by single-qubit von Neumann entropies.

arXiv:1109.1696•Physical Review A•Nov 2, 2011•122 citations

Entanglement of formation and quantum discord in multipartite j-spin coherent states

H. Baba, W. Kaydi, Mohammed Daoud A +1 more

We study the entanglement of formation and the quantum discord contained in even and odd multipartite [Formula: see text]-spin coherent states. The key element of this investigation is the fact that a single [Formula: see text]-spin coherent state is viewed as comprising [Formula: see text] qubit states. We compute the quantum correlations present in the n even and odd [Formula: see text]-spin coherent states by considering all possible bipartite splits of the multipartite system. We discuss the different bi-partition schemes of quantum systems and we examine in detail the conservation rules governing the distribution of quantum correlations between the different qubits of the multipartite system. Finally, we derive the explicit expressions of quantum correlations present in even and odd spin coherent states decomposed in four spin sub-systems. We also analyze the properties of monogamy and we show in particular that the entanglement of the formation and the quantum discord obey the relation of monogamy only for even multipartite [Formula: see text]-spin coherent states.

International Journal of Modern Physics B•Oct 2, 2020•6 citations

DYNAMICS OF QUANTUM CORRELATIONS IN TWO-QUBIT SYSTEMS WITHIN NON-MARKOVIAN ENVIRONMENTS

Rosario Lo Franco, Bruno Bellomo, Sabrina Maniscalco +1 more

Knowledge of the dynamical behavior of correlations with no classical counterpart, like entanglement, nonlocal correlations and quantum discord, in open quantum systems is of primary interest because of the possibility to exploit these correlations for quantum information tasks. Here we review some of the most recent results on the dynamics of correlations in bipartite systems embedded in non-Markovian environments that, with their memory effects, influence in a relevant way the system dynamics and appear to be more fundamental than the Markovian ones for practical purposes. Firstly, we review the phenomenon of entanglement revivals in a two-qubit system for both independent environments and a common environment. We then consider the dynamics of quantum discord in non-Markovian dephasing channel and briefly discuss the occurrence of revivals of quantum correlations in classical environments.

arXiv:1205.6419•International Journal of Modern Physics B•Oct 24, 2012•252 citations

Entanglement Dynamics of Photon-Added Quasi-Bell Coherent States

Mounaim Hamdoune, Mohammed Daoud A

Abstract Photon-added coherent states (PACS) represent a critical bridge between classical coherent states and quantum Fock states, exhibiting non-classical properties such as squeezing and sub-Poissonian statistics. In this work, we investigate the entanglement properties of quasi-Bell states constructed from photon-added coherent states, with a focus on the concurrence and entanglement of formation under varying photon excitation numbers m and coherent state amplitudes |α|. By leveraging the mathematical framework of Glauber’s coherent states and Laguerre polynomial normalization, we derive analytical expressions for the overlap between |α, m⟩ and | − α, m⟩, and analyze their suitability for qubit encoding. Our results reveal that for |α| ≥ 2, these states approximate orthogonal logical qubits, while smaller amplitudes exhibit m-dependent entanglement degradation. Numerical simulations demonstrate that entanglement of formation E12 approaches unity for large |α|, independent of m, but diminishes with increasing m in the weak-field regime (|α|2 < 1.5). These findings advance the understanding of photon-added states in quantum information protocols, offering insights into decoherence mitigation and resource-efficient qubit design.

•Aug 26, 2025•0 citations
A model of dynamics of quantum correlations of two modes quasi-Bell cat states, based on Glauber coherent states, is considered. The analytic expressions of pairwise entanglement of formation, quantum discord and its geometrized variant are explicitly derived. We analyze the distribution of quantum correlations between the two modes and the environment. We show that, in contrast with squared concurrence, entanglement of formation, quantum discord and geometric quantum discord do not follow the property of monogamy except in some particular situations that we discuss.
The evolution of pairwise quantum correlations of Bell cat-states under amplitude damping is examined using the concept of quantum discord which goes beyond entanglement. A closed expression of the quantum discord is explicitly derived. We used of the Koashi-Winter relation. A relation which facilitates the optimization process of the conditional entropy. We also discuss the temporal evolution of bipartite quantum correlations under a dephasing channel and compare the behaviors of quantum discord and entanglement whose properties are characterized through the concurrence.
The evolution of pairwise quantum correlations of Bell cat states under amplitude damping is examined using the concept of quantum discord which goes beyond entanglement. A closed expression of the quantum discord is explicitly derived. We used the Koashi–Winter relation, a relation which facilitates the optimization process of the conditional entropy. We also discuss the temporal evolution of bipartite quantum correlations under a dephasing channel and compare the behaviors of quantum discord and entanglement whose properties are characterized through the concurrence.
In contrast with entanglement, as measured by concurrence, in general, quantum discord does not possess the property of monogamy; that is, there is no tradeoff between the quantum discord shared by a pair of subsystems and the quantum discord that both of them can share with a third party. Here, we show that, as far as monogamy is considered, quantum discord of pure states is equivalent to the entanglement of formation. This result allows one to analytically prove that none of the pure three-qubit states belonging to the subclass of WWW states is monogamous. A suitable physical interpretation of the meaning of the correlation information as a quantifier of monogamy for the total information is also given. Finally, we prove that, for rank 2 two-qubit states, discord and classical correlations are bounded from above by single-qubit von Neumann entropies.
We study the entanglement of formation and the quantum discord contained in even and odd multipartite [Formula: see text]-spin coherent states. The key element of this investigation is the fact that a single [Formula: see text]-spin coherent state is viewed as comprising [Formula: see text] qubit states. We compute the quantum correlations present in the n even and odd [Formula: see text]-spin coherent states by considering all possible bipartite splits of the multipartite system. We discuss the different bi-partition schemes of quantum systems and we examine in detail the conservation rules governing the distribution of quantum correlations between the different qubits of the multipartite system. Finally, we derive the explicit expressions of quantum correlations present in even and odd spin coherent states decomposed in four spin sub-systems. We also analyze the properties of monogamy and we show in particular that the entanglement of the formation and the quantum discord obey the relation of monogamy only for even multipartite [Formula: see text]-spin coherent states.
Knowledge of the dynamical behavior of correlations with no classical counterpart, like entanglement, nonlocal correlations and quantum discord, in open quantum systems is of primary interest because of the possibility to exploit these correlations for quantum information tasks. Here we review some of the most recent results on the dynamics of correlations in bipartite systems embedded in non-Markovian environments that, with their memory effects, influence in a relevant way the system dynamics and appear to be more fundamental than the Markovian ones for practical purposes. Firstly, we review the phenomenon of entanglement revivals in a two-qubit system for both independent environments and a common environment. We then consider the dynamics of quantum discord in non-Markovian dephasing channel and briefly discuss the occurrence of revivals of quantum correlations in classical environments.
Abstract Photon-added coherent states (PACS) represent a critical bridge between classical coherent states and quantum Fock states, exhibiting non-classical properties such as squeezing and sub-Poissonian statistics. In this work, we investigate the entanglement properties of quasi-Bell states constructed from photon-added coherent states, with a focus on the concurrence and entanglement of formation under varying photon excitation numbers m and coherent state amplitudes |α|. By leveraging the mathematical framework of Glauber’s coherent states and Laguerre polynomial normalization, we derive analytical expressions for the overlap between |α, m⟩ and | − α, m⟩, and analyze their suitability for qubit encoding. Our results reveal that for |α| ≥ 2, these states approximate orthogonal logical qubits, while smaller amplitudes exhibit m-dependent entanglement degradation. Numerical simulations demonstrate that entanglement of formation E12 approaches unity for large |α|, independent of m, but diminishes with increasing m in the weak-field regime (|α|2 < 1.5). These findings advance the understanding of photon-added states in quantum information protocols, offering insights into decoherence mitigation and resource-efficient qubit design.