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

New Journal of Physics

Time evolution of quantum entanglement of an EPR pair in a localized environment

Jia Wang, Xia-Ji Liu, Hui Hu

Published Apr 16, 2018• 5 citations
Publisher

Abstract

The Einstein–Podolsky–Rosen (EPR) pair of qubits plays a critical role in many quantum protocol applications such as quantum communication and quantum teleportation. Due to interactions with the environment, an EPR pair can lose its entanglement and no longer serve as a useful quantum resource. On the other hand, it has been suggested that introducing disorder into environment might help prevent thermalization and improve the preservation of entanglement. Here, we theoretically investigate the time evolution of quantum entanglement of an EPR pair in a random-field XXZ spin chain model in the Anderson localized (AL) and many-body localized (MBL) phase. We find that the entanglement between qubits decreases and approaches a plateau in the AL phase, but shows a power-law decrease after some critical time determined by the interaction strength in the MBL phase. Our findings shed light on applying AL/MBL to improve quantum information storage, and can be used as a practical indicator to distinguish the AL and MBL phase.

DOI
10.1088/1367-2630/aabe3d

Related papers

Time Evolution of Quantum Entanglement of an EPR Pair in a Localized Environment

Jia Wang, Xia-Ji Liu, Hui Hu

The Einstein-Podolsky-Rosen (EPR) pair of qubits plays a critical role in many quantum protocol applications such as quantum communication and quantum teleportation. Due to interactions with the environment, an EPR pair can lose its entanglement and no longer serve as a useful quantum resource. On the other hand, it has been suggested that introducing disorder into environment might help prevent thermalization and improve the preservation of entanglement. Here, we theoretically investigate the time evolution of quantum entanglement of an EPR pair in a random-field XXZ spin chain model in the Anderson localized (AL) and many-body localized (MBL) phase. We find that the entanglement between qubits decreases and approaches a plateau in the AL phase, but shows a power-law decrease after some critical time determined by the interaction strength in the MBL phase. Our findings shed light on applying AL/MBL to improve quantum information storage, and can be used as a practical indicator to distinguish the AL and MBL phase.

arXiv:1701.03565•Jan 13, 2017•0 citations

Trends of information backflow in disordered spin chains

Sudipto Singha Roy, Utkarsh Mishra, Debraj Rakshit

We investigate the trends of information backflow associated with the dynamics of a sub-part of a disordered spin-1/2 transverse field Heisenberg chain for different regimes of the Hamiltonian. Towards this aim, the decay profile of bipartite entanglement shared between a probe-qubit and a system-qubit (sub-part) of the chain is monitored in time. A clear shift in the trends of the decay profiles of the bipartite entanglement from monotonic in the low-disorder limit to non-monotonic in the moderately large disorder limit occurs due to strong information backflow from the environment (complementary part) to the system-qubit. A connection between environmental interruption caused by the information backflow and the disorder strength is established by examining the entanglement revival frequencies. The growth patterns of the revival frequencies in the localized phase plays an instrumental role to effectively distinguish an interacting system (many-body localized) from its non-interacting (Anderson localized) counterpart.

arXiv:1811.08421•Europhysics Letters (EPL)•Mar 12, 2020•3 citations

Time evolution of entanglement in a four-qubit Heisenberg chain

Hassan Pakarzadeh, Zahra Norouzi, Javad Vahedi

The phenomenon of quantum entanglement has a very important role in quantum mechanics. Particularly, the quantum spin chain provides a platform for theoretical and experimental investigation of many-body entanglement. In this paper, we investigate time evolution of entanglement in a four-qubit anisotropic Heisenberg XXZ chain with nearest neighboring (NN), the next nearest neighboring (NNN), and the Dzialoshinskii-Moriya (DM) interactions. Calculations of the entanglement evolution of the Werner state carried out in terms of concurrence for selected ranges of control parameters such as DM interaction, frustration, etc. The results show that for the Werner state, DM interaction and the frustration parameters play important roles. Furthermore, results show that the time evolution of the Werner state entanglement may be useful to capture the quantum phase transitions in quantum magnetic systems.

Quantum Information and Computation•Aug 1, 2020•1 citation

On the Fidelity Distribution of Link-level Entanglements under Purification

Karim S. Elsayed, Wasiur R. KhudaBukhsh, Amr Rizk

Quantum entanglement is the key to quantum communications over considerable distances. The first step for entanglement distribution among quantum communication nodes is to generate link-level Einstein-Podolsky-Rosen (EPR) pairs between adjacent communication nodes. EPR pairs may be continuously generated and stored in a few quantum memories to be ready for utilization by quantum applications. A major challenge is that qubits suffer from unavoidable noise due to their interaction with the environment, which is called decoherence. This decoherence results in the known exponential decay model of the fidelity of the qubits with time, thus, limiting the lifetime of a qubit in a quantum memory and the performance of quantum applications. In this paper, we evaluate the fidelity of the stored EPR pairs under two opposite dynamical and probabilistic phenomena, first, the aforementioned decoherence and second purification, i.e. an operation to improve the fidelity of an EPR pair at the expense of sacrificing another EPR pair. Instead of applying the purification as soon as two EPR pairs are generated, we introduce a Purification scheme Beyond the Generation time (PBG) of two EPR pairs. We analytically show the probability distribution of the fidelity of stored link-level EPR pairs in a system with two quantum memories at each node allowing a maximum of two stored EPR pairs. In addition, we apply a PBG scheme that purifies the two stored EPR pairs upon the generation of an additional one. We finally provide numerical evaluations of the analytical approach and show the fidelity-rate trade-off of the considered purification scheme.

arXiv:2310.18198•Oct 27, 2023•6 citations

Improving Steering and Entanglement by Local Filtering Operation under Noisy Channels

Qing-Yun Zhou, Fa Zhao, Dong Wang +1 more

In reality, a quantum system will inevitably interact with the environment around it, and this will lead to decoherence. In this paper, we mainly study quantum entanglement and Einstein–Podolsky–Rosen (EPR) steering of two-qubit system in some typical environments. Exactly, consider the initial two-qubit state to be the Werner-type state, we let one of the qubits pass through some different channels including amplitude damping (AD) channel, phase damping (PD) channel, phase flip (PF) channel, and bit flip (BF) channel. We research entanglement and EPR steering in the progress. Most importantly, we find that entanglement and EPR steering can be improved by local filtering operations with an appropriate k. Besides, we also give an example of the fact that the EPR steering is the proper subset of entanglement. These results will promote the application of the two quantum resources in quantum information tasks.

Journal of the Physical Society of Japan•Oct 24, 2022•1 citation

Dimensioning of Quantum Memories for Distilled Quantum EPR Packets

Lorenzo Valentini, Diego Forlivesi, Andrea Talarico +1 more

The quantum Internet envisions a network where information is transmitted through entanglement, with Einstein-Podolsky-Rosen (EPR) pairs serving as one of the fundamental carriers. In this work, we propose a framework for dimensioning quantum memories capable of storing distilled EPR pairs useful to transmitting and manage quantum error correcting codes. Using a Markov chain model, we capture the stochastic evolution of stored entangled states in quantum memories, linking memory performance to system parameters such as technology characteristics and initial entanglement fidelity. Building on this framework, we provide analytical tools and design principles for optimizing memory architectures that preserve high-fidelity entanglement over time, ensuring the availability of encoded quantum resources necessary for several operations in future quantum Internet infrastructures transmitting EPR packets.

quant-pharXiv:2604.13964•Apr 16, 2026•0 citations
The Einstein–Podolsky–Rosen (EPR) pair of qubits plays a critical role in many quantum protocol applications such as quantum communication and quantum teleportation. Due to interactions with the environment, an EPR pair can lose its entanglement and no longer serve as a useful quantum resource. On the other hand, it has been suggested that introducing disorder into environment might help prevent thermalization and improve the preservation of entanglement. Here, we theoretically investigate the time evolution of quantum entanglement of an EPR pair in a random-field XXZ spin chain model in the Anderson localized (AL) and many-body localized (MBL) phase. We find that the entanglement between qubits decreases and approaches a plateau in the AL phase, but shows a power-law decrease after some critical time determined by the interaction strength in the MBL phase. Our findings shed light on applying AL/MBL to improve quantum information storage, and can be used as a practical indicator to distinguish the AL and MBL phase.
The Einstein-Podolsky-Rosen (EPR) pair of qubits plays a critical role in many quantum protocol applications such as quantum communication and quantum teleportation. Due to interactions with the environment, an EPR pair can lose its entanglement and no longer serve as a useful quantum resource. On the other hand, it has been suggested that introducing disorder into environment might help prevent thermalization and improve the preservation of entanglement. Here, we theoretically investigate the time evolution of quantum entanglement of an EPR pair in a random-field XXZ spin chain model in the Anderson localized (AL) and many-body localized (MBL) phase. We find that the entanglement between qubits decreases and approaches a plateau in the AL phase, but shows a power-law decrease after some critical time determined by the interaction strength in the MBL phase. Our findings shed light on applying AL/MBL to improve quantum information storage, and can be used as a practical indicator to distinguish the AL and MBL phase.
We investigate the trends of information backflow associated with the dynamics of a sub-part of a disordered spin-1/2 transverse field Heisenberg chain for different regimes of the Hamiltonian. Towards this aim, the decay profile of bipartite entanglement shared between a probe-qubit and a system-qubit (sub-part) of the chain is monitored in time. A clear shift in the trends of the decay profiles of the bipartite entanglement from monotonic in the low-disorder limit to non-monotonic in the moderately large disorder limit occurs due to strong information backflow from the environment (complementary part) to the system-qubit. A connection between environmental interruption caused by the information backflow and the disorder strength is established by examining the entanglement revival frequencies. The growth patterns of the revival frequencies in the localized phase plays an instrumental role to effectively distinguish an interacting system (many-body localized) from its non-interacting (Anderson localized) counterpart.
The phenomenon of quantum entanglement has a very important role in quantum mechanics. Particularly, the quantum spin chain provides a platform for theoretical and experimental investigation of many-body entanglement. In this paper, we investigate time evolution of entanglement in a four-qubit anisotropic Heisenberg XXZ chain with nearest neighboring (NN), the next nearest neighboring (NNN), and the Dzialoshinskii-Moriya (DM) interactions. Calculations of the entanglement evolution of the Werner state carried out in terms of concurrence for selected ranges of control parameters such as DM interaction, frustration, etc. The results show that for the Werner state, DM interaction and the frustration parameters play important roles. Furthermore, results show that the time evolution of the Werner state entanglement may be useful to capture the quantum phase transitions in quantum magnetic systems.
Quantum entanglement is the key to quantum communications over considerable distances. The first step for entanglement distribution among quantum communication nodes is to generate link-level Einstein-Podolsky-Rosen (EPR) pairs between adjacent communication nodes. EPR pairs may be continuously generated and stored in a few quantum memories to be ready for utilization by quantum applications. A major challenge is that qubits suffer from unavoidable noise due to their interaction with the environment, which is called decoherence. This decoherence results in the known exponential decay model of the fidelity of the qubits with time, thus, limiting the lifetime of a qubit in a quantum memory and the performance of quantum applications. In this paper, we evaluate the fidelity of the stored EPR pairs under two opposite dynamical and probabilistic phenomena, first, the aforementioned decoherence and second purification, i.e. an operation to improve the fidelity of an EPR pair at the expense of sacrificing another EPR pair. Instead of applying the purification as soon as two EPR pairs are generated, we introduce a Purification scheme Beyond the Generation time (PBG) of two EPR pairs. We analytically show the probability distribution of the fidelity of stored link-level EPR pairs in a system with two quantum memories at each node allowing a maximum of two stored EPR pairs. In addition, we apply a PBG scheme that purifies the two stored EPR pairs upon the generation of an additional one. We finally provide numerical evaluations of the analytical approach and show the fidelity-rate trade-off of the considered purification scheme.
In reality, a quantum system will inevitably interact with the environment around it, and this will lead to decoherence. In this paper, we mainly study quantum entanglement and Einstein–Podolsky–Rosen (EPR) steering of two-qubit system in some typical environments. Exactly, consider the initial two-qubit state to be the Werner-type state, we let one of the qubits pass through some different channels including amplitude damping (AD) channel, phase damping (PD) channel, phase flip (PF) channel, and bit flip (BF) channel. We research entanglement and EPR steering in the progress. Most importantly, we find that entanglement and EPR steering can be improved by local filtering operations with an appropriate k. Besides, we also give an example of the fact that the EPR steering is the proper subset of entanglement. These results will promote the application of the two quantum resources in quantum information tasks.
The quantum Internet envisions a network where information is transmitted through entanglement, with Einstein-Podolsky-Rosen (EPR) pairs serving as one of the fundamental carriers. In this work, we propose a framework for dimensioning quantum memories capable of storing distilled EPR pairs useful to transmitting and manage quantum error correcting codes. Using a Markov chain model, we capture the stochastic evolution of stored entangled states in quantum memories, linking memory performance to system parameters such as technology characteristics and initial entanglement fidelity. Building on this framework, we provide analytical tools and design principles for optimizing memory architectures that preserve high-fidelity entanglement over time, ensuring the availability of encoded quantum resources necessary for several operations in future quantum Internet infrastructures transmitting EPR packets.