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:0812.4612 · Physical Review A

Tripartite entanglement witnesses and entanglement sudden death

Yaakov S. Weinstein

Published Jan 16, 2009• 79 citations
arXivHTMLPDF

Abstract

I explore entanglement dynamics in a three qubit system comparing the ability of entanglement witnesses to detect tripartite entanglement to the phenomenon of entanglement sudden death (ESD). Using a system subject to dephasing I invoke entanglement witnesses to detect tripartite Greenberger-Horne-Zeilinger (GHZ)-type and $W$-type entanglement and compare the evolution of their detection capabilities with the evolution of the negativity, bipartite concurrence, and tripartite negativity. Interestingly, I find a state in which there is no concurrence or tripartite negativity but there is entanglement. Finally, I utilize a three qubit quantum error correction code to address how ESD affects the abilities of quantum error correction.

DOI
10.1103/physreva.79.012318

Related papers

Entanglement dynamics in three-qubit X states

Yaakov S. Weinstein

I explore the entanglement dynamics of a three-qubit system in an initial $X$ state undergoing decoherence including the possible exhibition of entanglement sudden death. To quantify entanglement I utilize negativity measures and make use of appropriate entanglement witnesses. The negativity results are then extended to $X$ states with an arbitraty number of qubits. I also demonstrate nonstandard behavior of the tripartite negativity entanglement metric: its sudden appearance after some amount of decoherence, followed quickly by its disappearance. Finally, I solve for a lower bound on the three-qubit $X$-state concurrence, demonstrate when this bound goes to $0$, and outline simplifcations for the calculation of higher-order $X$-state concurrences.

arXiv:1004.3748•Physical Review A•Sep 27, 2010•46 citations

Entanglement dynamics for a six-qubit model in cavity QED

Zhong‐Xiao Man, Yun‐Jie Xia, Nguyen Ba An

We study entanglement dynamics for a six-qubit model in cavity QED, where three two-level atoms A , B and C are initially prepared in a Greenberger–Horne–Zeilinger (GHZ)-like state and locally coupled with the independent cavities a , b and c , respectively. We consider entanglement evolution via negativity for the tripartite subsystems of atoms and the corresponding cavities. By choosing two types of GHZ-like states as atomic initial states, we shall show that the entanglement of atoms may or may not exhibit entanglement sudden death (ESD) depending on the type of atomic initial state.

Journal of Physics B Atomic Molecular and Optical Physics•Jul 18, 2008•33 citations

Entanglement Evolution in a Five Qubit Error Correction Code

Yaakov S. Weinstein

In this paper I explore the entanglement evolution of qubits that are part of a five qubit quantum error correction code subject to various decohering environments. Specifically, I look for possible parallels between the entanglement degradation and the fidelity of the logical qubit of quantum information stored in the physical qubits. In addition, I note the possible exhibition of entanglement sudden death (ESD) due to decoherence and question whether ESD is actually a roadblock to successful quantum computation.

arXiv:1011.4900•Nov 22, 2010•0 citations

Entanglement sudden death in a quantum memory

Yaakov S. Weinstein

I explore the entanglement dynamics of multiqubit systems suitable for use as quantum memories: decoherence free subspaces and noiseless subsystems. The aim of this exploration is to determine how a complete loss of entanglement affects the ability of these error-avoidance techniques to protect quantum information. I utilize negativity and concurrence as entanglement measures and find no correlation between complete system loss of entanglement and the fidelity of the stored quantum information. These results complement previous results in which quantum protocols not explicitly based on entanglement exhibit little correlation between entanglement sudden death and the accuracy of the given protocol.

arXiv:0904.0956•Physical Review A•Aug 6, 2009•9 citations

Entanglement sudden death as an indicator of fidelity in a four-qubit cluster state

Yaakov S. Weinstein

I explore the entanglement evolution of a four-qubit cluster state in a dephasing environment concentrating on the phenomenon of entanglement sudden death (ESD). Specifically, I ask whether the onset of ESD has an effect on the utilization of this cluster state as a means of implementing a single-qubit rotation in the measurement-based cluster state model of quantum computation. To do this, I compare the evolution of the entanglement to the fidelity, a measure of how accurately the desired state (after the measurement-based operations) is achieved. I find that ESD does not cause a change in behavior or discontinuity in the fidelity but may indicate for certain states when the fidelity goes to 0.5.

arXiv:0902.2697•Physical Review A•May 19, 2009•18 citations

Decoherence-Induced Sudden Death of Entanglement and Bell Nonlocality

Dong-Gil Im, Yoon-Ho Kim

Decoherence due to the unwanted interaction between a quantum system and environment leads to the degradation of quantum coherence. In particular, for an entangled state, decoherence makes a loss of entanglement and Bell nonlocality known as entanglement sudden death (ESD), and Bell nonlocality sudden death (BNSD). Here, we theoretically investigate the entanglement and Bell nonlocality of a bipartite entangled state under three types of decoherence, amplitude damping, phase damping, and depolarizing. Our result provides the bound of decoherence strength that does not lose the entanglement and Bell nonlocality. In addition, we find two interesting features. One is that the entanglement can survive even though one of the entangled qubits is affected by a large strength of decoherence if the other qubit is affected by a small enough strength of decoherence except for the depolarizing. The second one is that when a specific form of entangled state is under amplitude damping, the Bell nonlocality shows an asymmetric behavior respect to the decoherence strengths on each qubit. Our work provides comprehensive information on ESD and BNSD for the bipartite entangled state which will be useful to implement quantum information processing in the presence of decoherence.

Photonics•Jan 24, 2022•6 citations
I explore entanglement dynamics in a three qubit system comparing the ability of entanglement witnesses to detect tripartite entanglement to the phenomenon of entanglement sudden death (ESD). Using a system subject to dephasing I invoke entanglement witnesses to detect tripartite Greenberger-Horne-Zeilinger (GHZ)-type and WWW-type entanglement and compare the evolution of their detection capabilities with the evolution of the negativity, bipartite concurrence, and tripartite negativity. Interestingly, I find a state in which there is no concurrence or tripartite negativity but there is entanglement. Finally, I utilize a three qubit quantum error correction code to address how ESD affects the abilities of quantum error correction.
I explore the entanglement dynamics of a three-qubit system in an initial XXX state undergoing decoherence including the possible exhibition of entanglement sudden death. To quantify entanglement I utilize negativity measures and make use of appropriate entanglement witnesses. The negativity results are then extended to XXX states with an arbitraty number of qubits. I also demonstrate nonstandard behavior of the tripartite negativity entanglement metric: its sudden appearance after some amount of decoherence, followed quickly by its disappearance. Finally, I solve for a lower bound on the three-qubit XXX-state concurrence, demonstrate when this bound goes to 000, and outline simplifcations for the calculation of higher-order XXX-state concurrences.
We study entanglement dynamics for a six-qubit model in cavity QED, where three two-level atoms A , B and C are initially prepared in a Greenberger–Horne–Zeilinger (GHZ)-like state and locally coupled with the independent cavities a , b and c , respectively. We consider entanglement evolution via negativity for the tripartite subsystems of atoms and the corresponding cavities. By choosing two types of GHZ-like states as atomic initial states, we shall show that the entanglement of atoms may or may not exhibit entanglement sudden death (ESD) depending on the type of atomic initial state.
In this paper I explore the entanglement evolution of qubits that are part of a five qubit quantum error correction code subject to various decohering environments. Specifically, I look for possible parallels between the entanglement degradation and the fidelity of the logical qubit of quantum information stored in the physical qubits. In addition, I note the possible exhibition of entanglement sudden death (ESD) due to decoherence and question whether ESD is actually a roadblock to successful quantum computation.
I explore the entanglement dynamics of multiqubit systems suitable for use as quantum memories: decoherence free subspaces and noiseless subsystems. The aim of this exploration is to determine how a complete loss of entanglement affects the ability of these error-avoidance techniques to protect quantum information. I utilize negativity and concurrence as entanglement measures and find no correlation between complete system loss of entanglement and the fidelity of the stored quantum information. These results complement previous results in which quantum protocols not explicitly based on entanglement exhibit little correlation between entanglement sudden death and the accuracy of the given protocol.
I explore the entanglement evolution of a four-qubit cluster state in a dephasing environment concentrating on the phenomenon of entanglement sudden death (ESD). Specifically, I ask whether the onset of ESD has an effect on the utilization of this cluster state as a means of implementing a single-qubit rotation in the measurement-based cluster state model of quantum computation. To do this, I compare the evolution of the entanglement to the fidelity, a measure of how accurately the desired state (after the measurement-based operations) is achieved. I find that ESD does not cause a change in behavior or discontinuity in the fidelity but may indicate for certain states when the fidelity goes to 0.5.
Decoherence due to the unwanted interaction between a quantum system and environment leads to the degradation of quantum coherence. In particular, for an entangled state, decoherence makes a loss of entanglement and Bell nonlocality known as entanglement sudden death (ESD), and Bell nonlocality sudden death (BNSD). Here, we theoretically investigate the entanglement and Bell nonlocality of a bipartite entangled state under three types of decoherence, amplitude damping, phase damping, and depolarizing. Our result provides the bound of decoherence strength that does not lose the entanglement and Bell nonlocality. In addition, we find two interesting features. One is that the entanglement can survive even though one of the entangled qubits is affected by a large strength of decoherence if the other qubit is affected by a small enough strength of decoherence except for the depolarizing. The second one is that when a specific form of entangled state is under amplitude damping, the Bell nonlocality shows an asymmetric behavior respect to the decoherence strengths on each qubit. Our work provides comprehensive information on ESD and BNSD for the bipartite entangled state which will be useful to implement quantum information processing in the presence of decoherence.