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

Journal of Optics B Quantum and Semiclassical Optics

Dynamics of quantum nonlocality for a hybrid entangled state in a thermal reservoir

Huai-Xin Lu, Bo Zhao, Meisheng Zhao, Jun Hai Guo, Zeng‐Bing Chen, Yong-De Zhang

Published Oct 30, 2002• 6 citations
Publisher

Abstract

In this paper, we have studied the dynamics of nonlocality for a hybrid entangled state in a thermal reservoir. The density operator of the system is obtained by using a superoperator method. The dynamics of nonlocality for the mixed hybrid entangled state is uncovered by using the Bell operator based on the ‘pseudospin operator’ for a light field (Chen Z B, Pan J W, Hou G and Zhang Y D 2002 Phys. Rev. Lett. 88 040406). The dynamics of nonlocality has also been studied using other Bell operators.

DOI
10.1088/1464-4266/4/6/307

Related papers

Dynamical nonlocality of the entangled coherent state in the phase damping model

Huai-Xin Lu, Yingde Li

This paper studies the dynamics of nonlocality for a bosonic entangled coherent state in a phase damping model. The density operator of the system is solved by using a superoperator method. The dynamics of nonlocality for the bosonic entangled coherent state is uncovered by the Bell operator based on the pseudospin operator of a light field. The dynamics of the nonlocality for this state has also been studied by other Bell operators. The result of the numerical calculations of the Bell function shows that the quantum nonlocality heavily depends on the chosen Bell operator.

Chinese Physics B•Jan 1, 2009•4 citations

Quantum nonlocality and entanglement for a two-mode squeezed vacuum state in a phase damping channel

Lu Huai-Xin

We study dynamics of quantum nonlocality and entanglement for a two-mode squeezed vacuum state in a phase damping channel. After getting the explicit expression of the density evolution operator of the system, we uncover the nonlocality of the state by introducing appropriate Bell operator based on the 'pseudospin operator'. The property of the entanglement for the state is also clear from the calculation of relative entropy of entanglement.

Chinese Journal of Quantum Electronics•Jan 1, 2005•0 citations

Nonlocality under Jaynes-Cummings evolution: Beyond pseudospin operators

Alexander Bernal, J.A. Casas, Jesús M. Moreno

We revisit the generation and evolution of Bell nonlocality in hybrid scenarios of which the dynamics is determined by the Jaynes-Cummings Hamiltonian, a relevant example of which is the atom-cavity system. Previous approaches evaluate the nonlocality through the well-known qubit-qubit Clauser-Horne-Shimony-Holt (CHSH) formulas, using combinations of pseudospin operators for the electromagnetic (EM) field observables. While such an approach is sensible, it is far from optimal. In the present work we have used recent results on optimal Bell violation in qubit-qudit systems, showing that the nonlocality is much greater than previously estimated, both with and without noise. In addition, we provide an optimal treatment of noise, ensuring that our results are the best possible within this framework. We illustrate the results using different initial states for the EM field, including squeezed and coherent states. In addition, we study the asymptotic behavior of the entanglement. Remarkably, starting with a generic separable pure coherent state, the asymptotic mixed state is entangled, though it does not violate CHSH inequalities.

arXiv:2410.10651•Physical Review A•Sep 18, 2025•0 citations

THE NONLOCALITY OF AN ENTANGLED COHERENT STATE AND ITS EVOLUTION BY USING PSEUDOSPIN OPERATORS

Gong Ren-shan

By using Bell CHSH inequality,nonlocality of a kind of entangled coherent state and its evolution in a vacuum thermal reservoir are studied.It is shown that nonlocality of the state are related with the phases.In this paper we just give the results when φ-2=0 is satisfied,on the other hand nonlocality of the state decreases gradually and disappears finally under the time evolution in a vacuum thermal reservoir.

Journal of Nanchang University•Jan 1, 2005•0 citations

Non-locality of Entangled Coherent States and Its Evolution in a Thermal Reservoir

GONGRen-Shan

Regarding the necessary and sufficient condition violating Bell-CHSH's inequality as criterion for nonlocality of entangled states, we present a perturbative calculation determining non-locality of evolving entangled states.Furthermore, by means of the perturbative calculation, the non-locality and its evolution of two kinds of entangled coherent states in a thermal reservoir are discussed.

理论物理通讯:英文版•Jan 1, 2005•0 citations

Dynamical Bell Nonlocality

Kuntal Sengupta

Quantum mechanics is a highly nonlocal theory of nature. Quantum systems exhibit correlations which cannot be described by any classical theory of locality. We develop the resource theory of dynamical Bell nonlocality, which includes bipartite states, classical channels, quantum channels and measurements. In the state scenario, all separable states are Bell local. However, there exist mixed bipartite entangled states which also admit Bell local behaviour. To address this anomaly, we introduce the notion of fully Bell locality and show that all entangled states are Bell nonlocal, in the sense that they can be used to simulate at least one nonlocal bipartite Positive Operator Valued Measure (POVM) channel. We take a step further and generalise this result to bipartite entangled quantum channels. We then generalize the CHSH inequality from bipartite classical channels to bipartite POVM channels and devise a technique to check if a given bipartite POVM channel is nonlocal or not. Finally we provide a systematic method to quantify Bell nonlocality of bipartite quantum channels by extending any monotone for Bell nonlocality of classical channels to quantum channels and also introduce the precise definition of relative entropy of Bell nonlocality. We leave some open problems in the way.

•Sep 12, 2020•0 citations
In this paper, we have studied the dynamics of nonlocality for a hybrid entangled state in a thermal reservoir. The density operator of the system is obtained by using a superoperator method. The dynamics of nonlocality for the mixed hybrid entangled state is uncovered by using the Bell operator based on the ‘pseudospin operator’ for a light field (Chen Z B, Pan J W, Hou G and Zhang Y D 2002 Phys. Rev. Lett. 88 040406). The dynamics of nonlocality has also been studied using other Bell operators.
This paper studies the dynamics of nonlocality for a bosonic entangled coherent state in a phase damping model. The density operator of the system is solved by using a superoperator method. The dynamics of nonlocality for the bosonic entangled coherent state is uncovered by the Bell operator based on the pseudospin operator of a light field. The dynamics of the nonlocality for this state has also been studied by other Bell operators. The result of the numerical calculations of the Bell function shows that the quantum nonlocality heavily depends on the chosen Bell operator.
We revisit the generation and evolution of Bell nonlocality in hybrid scenarios of which the dynamics is determined by the Jaynes-Cummings Hamiltonian, a relevant example of which is the atom-cavity system. Previous approaches evaluate the nonlocality through the well-known qubit-qubit Clauser-Horne-Shimony-Holt (CHSH) formulas, using combinations of pseudospin operators for the electromagnetic (EM) field observables. While such an approach is sensible, it is far from optimal. In the present work we have used recent results on optimal Bell violation in qubit-qudit systems, showing that the nonlocality is much greater than previously estimated, both with and without noise. In addition, we provide an optimal treatment of noise, ensuring that our results are the best possible within this framework. We illustrate the results using different initial states for the EM field, including squeezed and coherent states. In addition, we study the asymptotic behavior of the entanglement. Remarkably, starting with a generic separable pure coherent state, the asymptotic mixed state is entangled, though it does not violate CHSH inequalities.
Quantum mechanics is a highly nonlocal theory of nature. Quantum systems exhibit correlations which cannot be described by any classical theory of locality. We develop the resource theory of dynamical Bell nonlocality, which includes bipartite states, classical channels, quantum channels and measurements. In the state scenario, all separable states are Bell local. However, there exist mixed bipartite entangled states which also admit Bell local behaviour. To address this anomaly, we introduce the notion of fully Bell locality and show that all entangled states are Bell nonlocal, in the sense that they can be used to simulate at least one nonlocal bipartite Positive Operator Valued Measure (POVM) channel. We take a step further and generalise this result to bipartite entangled quantum channels. We then generalize the CHSH inequality from bipartite classical channels to bipartite POVM channels and devise a technique to check if a given bipartite POVM channel is nonlocal or not. Finally we provide a systematic method to quantify Bell nonlocality of bipartite quantum channels by extending any monotone for Bell nonlocality of classical channels to quantum channels and also introduce the precise definition of relative entropy of Bell nonlocality. We leave some open problems in the way.