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:1603.09119 · Physical Review A

Time-invariant entanglement and sudden death of nonlocality

Bi‐Heng Liu, Xiao-Min Hu, Jiang-Shan Chen, Chao Zhang, Yun‐Feng Huang, Chuan-Feng Li, Guang-Can Guo, Göktuğ Karpat, F. F. Fanchini, Jyrki Piilo, Sabrina Maniscalco

Published Dec 9, 2016• 19 citations
arXivHTMLPDF

Abstract

We investigate both theoretically and experimentally the dynamics of entanglement and nonlocality for two qubits immersed in a global pure dephasing environment. We demonstrate the existence of a class of states for which entanglement is forever frozen during the dynamics, even if the state of the system does evolve. At the same time nonlocal correlations, quantified by the violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality, either undergo sudden death or are trapped during the dynamics.

DOI
10.1103/physreva.94.062107

Related papers

Revival of Bell nonlocality across a quantum spin chain

Josep Amengual i Batle, M.M. Abutalib, S. Abdalla +1 more

The transmission of pure and mixed states along a quantum spin chain is investigated. Nonlocality between two qubits will evolve as it is transmitted through the quantum channel in a way that may violate or not the Clauser–Horne–Shimony–Holt (CHSH) Bell inequality at different times. This violation of local realism is analogue to the so-called sudden death and sudden birth features of entanglement. In the quantum channel, which will turn to be a damping one, some (mixed) states will be preferred according to the nature of the quantum correlations that are preserved during the evolution along the spin chain.

International Journal of Quantum Information•Oct 1, 2016•13 citations

Sudden death of entanglement in fermionic systems under collective decoherence

D G Bussandri, A P Majtey, A Valdés-Hernández

Abstract We analyze the dynamics of entanglement due to decoherence in a system of two identical fermions with spin 3/2 interacting with a global bosonic environment. We make use of an appropriate measure of the so-called fermionic entanglement to quantify the fermionic correlations, and compare the dynamical effects due to decoherence with those that arise in a pair of distinguishable qubits immersed in the same environment. According to the system’s initial state, three types of qualitatively different dynamics are identified: i) invariant regime , corresponding to initial states that belong to a decoherence free subspace (DFS), which maintain invariant their entanglement and coherence throughout the evolution; ii) exponential decay , corresponding to initial states orthogonal to the DFS, and evolve towards states whose entanglement and coherence decrease exponentially; iii) entanglement sudden death , corresponding to initial states that have some overlap with the DFS and exhibit a richer dynamics leading, in particular, to the sudden death of the fermionic entanglement, while the coherence decays exponentially. Our analysis offers insights into the dynamics of entanglement in open systems of identical particles and into the existence of decoherence free subspaces and entanglement sudden death in indistinguishable-fermion systems.

arXiv:2008.08545•Journal of Physics A Mathematical and Theoretical•Aug 14, 2020•7 citations

Ubiquitous Nonlocal Entanglement with Majorana Zero Modes

Alessandro Romito, Yuval Gefen

Entanglement in quantum mechanics contradicts local realism and is a manifestation of quantum nonlocality. Its presence can be detected through the violation of Bell, or Clauser-Horne-Shimony-Holt (CHSH) inequalities. Paradigmatic quantum systems provide examples of both, nonentangled and entangled states. Here, we consider a minimal complexity setup consisting of six Majorana zero modes. We find that any allowed state in the degenerate Majorana space is nonlocally entangled. We show how to measure (with available techniques) the CHSH-violating correlations using either intermediate strength or weak measurement protocols.

arXiv:1703.01841•Physical Review Letters•Oct 13, 2017•16 citations

Sudden death of entanglement in fermionic systems under collective decoherence

Bussandri, Diego, Majtey, Ana Paula, Valdés Hernández, Andrea

We analyze the dynamics of entanglement due to decoherence in asystem of two identical fermions with spin 3/2 interacting with a global bosonicenvironment. We make use of an appropriate measure of the so-called fermionicentanglement to quantify the fermionic correlations, and compare the dynamicaleffects due to decoherence with those that arise in a pair of distinguishablequbits immersed in the same environment. According to the system?s initialstate, three types of qualitatively different dynamics are identified: i) invariantregime, corresponding to initial states that belong to a decoherence free subspace(DFS), which maintain invariant their entanglement and coherence throughoutthe evolution; ii) exponential decay, corresponding to initial states orthogonal tothe DFS, and evolve towards states whose entanglement and coherence decreaseexponentially; iii) entanglement sudden death, corresponding to initial states that havesome overlap with the DFS and exhibit a richer dynamics leading, in particular,to the sudden death of the fermionic entanglement, while the coherence decaysexponentially. Our analysis offers insights into the dynamics of entanglementin open systems of identical particles and into the existence of decoherence freesubspaces and entanglement sudden death in indistinguishable-fermion systems.

•Jan 1, 2020•5 citations

Entanglement as upper bound for the nonlocality of a general two-qubit system

Zhaofeng Su, Haisheng Tan, Xiang‐Yang Li

Nonlocality and entanglement are not only the fundamental characteristics of quantum mechanics but also important resources for quantum information and computation applications. Exploiting the quantitative relationship between the two different resources is of both theoretical and practical significance. The common choice for quantifying the nonlocality of a two-qubit state is the maximal violation of the Clauser-Horne-Shimony-Holt inequality. That for entanglement is entanglement of formation, which is a function of the concurrence. In this paper, we systematically investigate the quantitative relationship between the entanglement and nonlocality of a general two-qubit system. We rederive a known upper bound on the nonlocality of a general two-qubit state, which depends on the state's entanglement. We investigate the condition that the nonlocality of two different two-qubit states can be optimally stimulated by the same nonlocality test setting and find the class of two-qubit state pairs that have this property. Finally, we obtain the necessary and sufficient condition that the upper bound can be reached.

arXiv:2004.08337•Physical Review A•Apr 14, 2020•21 citations

Sudden Death of Entanglement in a Two-Qubit System Coupled to a Small Environment

G. L. Deçordi, A. Vidiella-Barranco

We study the entanglement dynamics of two interacting qubits, having only one of them coupled to a small environment (single mode thermal field). We verify the existence of sudden death of entanglement in the system.

The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting•Jan 1, 2019•0 citations
We investigate both theoretically and experimentally the dynamics of entanglement and nonlocality for two qubits immersed in a global pure dephasing environment. We demonstrate the existence of a class of states for which entanglement is forever frozen during the dynamics, even if the state of the system does evolve. At the same time nonlocal correlations, quantified by the violation of the Clauser-Horne-Shimony-Holt (CHSH) inequality, either undergo sudden death or are trapped during the dynamics.
The transmission of pure and mixed states along a quantum spin chain is investigated. Nonlocality between two qubits will evolve as it is transmitted through the quantum channel in a way that may violate or not the Clauser–Horne–Shimony–Holt (CHSH) Bell inequality at different times. This violation of local realism is analogue to the so-called sudden death and sudden birth features of entanglement. In the quantum channel, which will turn to be a damping one, some (mixed) states will be preferred according to the nature of the quantum correlations that are preserved during the evolution along the spin chain.
Abstract We analyze the dynamics of entanglement due to decoherence in a system of two identical fermions with spin 3/2 interacting with a global bosonic environment. We make use of an appropriate measure of the so-called fermionic entanglement to quantify the fermionic correlations, and compare the dynamical effects due to decoherence with those that arise in a pair of distinguishable qubits immersed in the same environment. According to the system’s initial state, three types of qualitatively different dynamics are identified: i) invariant regime , corresponding to initial states that belong to a decoherence free subspace (DFS), which maintain invariant their entanglement and coherence throughout the evolution; ii) exponential decay , corresponding to initial states orthogonal to the DFS, and evolve towards states whose entanglement and coherence decrease exponentially; iii) entanglement sudden death , corresponding to initial states that have some overlap with the DFS and exhibit a richer dynamics leading, in particular, to the sudden death of the fermionic entanglement, while the coherence decays exponentially. Our analysis offers insights into the dynamics of entanglement in open systems of identical particles and into the existence of decoherence free subspaces and entanglement sudden death in indistinguishable-fermion systems.
Entanglement in quantum mechanics contradicts local realism and is a manifestation of quantum nonlocality. Its presence can be detected through the violation of Bell, or Clauser-Horne-Shimony-Holt (CHSH) inequalities. Paradigmatic quantum systems provide examples of both, nonentangled and entangled states. Here, we consider a minimal complexity setup consisting of six Majorana zero modes. We find that any allowed state in the degenerate Majorana space is nonlocally entangled. We show how to measure (with available techniques) the CHSH-violating correlations using either intermediate strength or weak measurement protocols.
We analyze the dynamics of entanglement due to decoherence in asystem of two identical fermions with spin 3/2 interacting with a global bosonicenvironment. We make use of an appropriate measure of the so-called fermionicentanglement to quantify the fermionic correlations, and compare the dynamicaleffects due to decoherence with those that arise in a pair of distinguishablequbits immersed in the same environment. According to the system?s initialstate, three types of qualitatively different dynamics are identified: i) invariantregime, corresponding to initial states that belong to a decoherence free subspace(DFS), which maintain invariant their entanglement and coherence throughoutthe evolution; ii) exponential decay, corresponding to initial states orthogonal tothe DFS, and evolve towards states whose entanglement and coherence decreaseexponentially; iii) entanglement sudden death, corresponding to initial states that havesome overlap with the DFS and exhibit a richer dynamics leading, in particular,to the sudden death of the fermionic entanglement, while the coherence decaysexponentially. Our analysis offers insights into the dynamics of entanglementin open systems of identical particles and into the existence of decoherence freesubspaces and entanglement sudden death in indistinguishable-fermion systems.
Nonlocality and entanglement are not only the fundamental characteristics of quantum mechanics but also important resources for quantum information and computation applications. Exploiting the quantitative relationship between the two different resources is of both theoretical and practical significance. The common choice for quantifying the nonlocality of a two-qubit state is the maximal violation of the Clauser-Horne-Shimony-Holt inequality. That for entanglement is entanglement of formation, which is a function of the concurrence. In this paper, we systematically investigate the quantitative relationship between the entanglement and nonlocality of a general two-qubit system. We rederive a known upper bound on the nonlocality of a general two-qubit state, which depends on the state's entanglement. We investigate the condition that the nonlocality of two different two-qubit states can be optimally stimulated by the same nonlocality test setting and find the class of two-qubit state pairs that have this property. Finally, we obtain the necessary and sufficient condition that the upper bound can be reached.