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 Physics A Mathematical and General

Continuous variable entanglement swapping

Masashi Ban

Published Jul 22, 2004• 12 citations
Publisher

Abstract

A sequence of entanglement swapping of continuous variables is considered. It is classified into one-way entanglement swapping and two-way entanglement swapping, where the former (the latter) uses one-way (two-way) classical communication. When resources of quantum entanglement are bipartite Gaussian states, it is shown that the one-way entanglement swapping is superior to the two-way entanglement swapping. This means that although the entanglement swapping is performed the same number of times, there is a case that the one-way entanglement swapping can yield an entangled state while the two-way entanglement swapping cannot.

DOI
10.1088/0305-4470/37/31/l01

Related papers

Non-Gaussian entanglement swapping

Fabio Dell’Anno, Daniela Buono, Gaetano Nocerino +2 more

We investigate the continuous-variable entanglement swapping protocol in a non-Gaussian setting, with non- Gaussian states employed either as entangled inputs and/or as swapping resources. The quality of the swapping protocol is assessed in terms of the teleportation fidelity achievable when using the swapped states as shared entangled resources in a teleportation protocol. We thus introduce a two-step cascaded quantum communication scheme that includes a swapping protocol followed by a teleportation protocol. The swapping protocol is fed by a general class of tunable non-Gaussian states, the squeezed Bell states, which, by means of controllable free parameters, allows for a continuous morphing from Gaussian twin beams up to maximally non-Gaussian squeezed number states. In the realistic instance, taking into account the effects of losses and imperfections, we show that as the input two-mode squeezing increases, optimized non-Gaussian swapping resources allow for a monotonically increasing enhancement of the fidelity compared to the corresponding Gaussian setting. This result implies that the use of non-Gaussian resources is necessary to guarantee the success of continuous-variable entanglement swapping in the presence of decoherence.

arXiv:1606.03010•Jun 9, 2016•0 citations

Continuous-Variable Entanglement Swapping

Kevin Marshall, Christian Weedbrook

We present a very brief overview of entanglement swapping as it relates to continuous-variable quantum information. The technical background required is discussed and the natural link to quantum teleportation is established before discussing the nature of Gaussian entanglement swapping. The limitations of Gaussian swapping are introduced, along with the general applications of swapping in the context of to quantum communication and entanglement distribution. In light of this, we briefly summarize a collection of entanglement swapping schemes which incorporate a non-Gaussian ingredient and the benefits of such schemes are noted. Finally, we motivate the need to further study and develop such schemes by highlighting requirements of a continuous-variable repeater.

Entropy•May 13, 2015•8 citations

Deterministic Entanglement Swapping with Hybrid Discrete- and Continuous-Variable Systems

Shou‐Bang Yang, Wen Ning, Ri‐Hua Zheng +2 more

The study of entanglement between discrete and continuous variables is an important theoretical and experimental topic in quantum information processing, for which entanglement swapping is one of the interesting elements. Entanglement swapping allows two particles without interacting with each other in any way, to form an entangled state by the action of another pair of entangled particles. In this paper, we propose an experimentally feasible scheme to realize deterministic entanglement swapping in the hybrid system with discrete and continuous variables. The process is achieved by preparing two pairs of entangled states, each is formed by a qubit and two quasi-orthogonal coherent state elements of a cavity, performing a Bell-state analysis through nonlocal operations on the continuous variable states of the two cavities, and projecting the two qubits into a maximally entangled state. The present scheme may be applied to other physical systems sustaining such hybrid discrete and continuous forms, providing a typical paradigm for entanglement manipulation through deterministic swapping operations.

Photonics•May 25, 2022•3 citations

Entanglement swapping of tripartite entangled coherent state by linear optics devices

Dongmei Li

A scheme for the entanglement swapping of entangled states with continuous variable is presented, in which the bipartite maximally entangled coherent state serves as the quantum channel.With the help of the idea of teleportation,using beam splitter and phase-shifter,entanglement swapping of tripartite entangled coherent state can be realized.In this scheme,the entanglement swapping is failure only for one measurement process.The failure probability is very small.The detail results show that the probability and the minimum of total average fidelity for successful swapping an arbitrary tripartite entangled coherent state is nearly 1 when the mean number of photons is larger than 2.

Chinese Journal of Quantum Electronics•Jan 1, 2009•0 citations

Entanglement swapping of two-mode Gaussian states in a thermal environment

Hongrong Li, Fuli Li, Yang Yang +1 more

Entanglement swapping of two-mode Gaussian states is investigated by use of quantum teleportation protocol of continuous variables. In the entanglement swapping protocol, we take the two-mode squeezed vacuum which is exposed in a thermal environment as a mixed-quantum-channel state and a two-mode standard form Gaussian state as an input state to be teleported. When the input state is pure, we find that the swapped state is inseparable if and only if both the input state and the quantum-channel state are entangled. When the input state is mixed and entangled, we find that the swapped state is inseparable only if the quantum-channel state is sufficiently much entangled. We also notice that the required minimum entanglement in the mixed quantum channel to maintain entanglement in the swapped state strongly depends on the global purity of the input state.

Physical Review A•Feb 18, 2005•22 citations

Continuous-variable entanglement swapping with photon subtraction

Na Wang, Meihong Wang, Xiaolong Su

Entanglement swapping, which establishes entanglement between two independent and distant entangled states, is a key element of a quantum repeater in an entanglement-based quantum network. In continuous-variable (CV) entanglement swapping, it is essential to enhance the entanglement of entanglement swapping because it decreases with loss and noise in the quantum channel. Here, we propose a scheme of enhancing entanglement of CV entanglement swapping by a photon subtraction (PS) operation in noisy channels. We apply both one- and two-sided PS operations in CV entanglement swapping through lossy single- and dual-channel transmission schemes, respectively. In the lossy channel, we show that the two-sided PS operation enables one to obtain higher entanglement and longer transmission distance compared to the one-sided PS operation. Furthermore, we show that the two-sided PS operation can enhance the entanglement of the entanglement swapping in the noisy single-channel CV entanglement swapping. Our results provide a feasible solution to enhance entanglement of CV entanglement swapping, and they have potential applications in building quantum repeaters.

Physical Review A•Jul 3, 2024•9 citations
A sequence of entanglement swapping of continuous variables is considered. It is classified into one-way entanglement swapping and two-way entanglement swapping, where the former (the latter) uses one-way (two-way) classical communication. When resources of quantum entanglement are bipartite Gaussian states, it is shown that the one-way entanglement swapping is superior to the two-way entanglement swapping. This means that although the entanglement swapping is performed the same number of times, there is a case that the one-way entanglement swapping can yield an entangled state while the two-way entanglement swapping cannot.
We investigate the continuous-variable entanglement swapping protocol in a non-Gaussian setting, with non- Gaussian states employed either as entangled inputs and/or as swapping resources. The quality of the swapping protocol is assessed in terms of the teleportation fidelity achievable when using the swapped states as shared entangled resources in a teleportation protocol. We thus introduce a two-step cascaded quantum communication scheme that includes a swapping protocol followed by a teleportation protocol. The swapping protocol is fed by a general class of tunable non-Gaussian states, the squeezed Bell states, which, by means of controllable free parameters, allows for a continuous morphing from Gaussian twin beams up to maximally non-Gaussian squeezed number states. In the realistic instance, taking into account the effects of losses and imperfections, we show that as the input two-mode squeezing increases, optimized non-Gaussian swapping resources allow for a monotonically increasing enhancement of the fidelity compared to the corresponding Gaussian setting. This result implies that the use of non-Gaussian resources is necessary to guarantee the success of continuous-variable entanglement swapping in the presence of decoherence.
We present a very brief overview of entanglement swapping as it relates to continuous-variable quantum information. The technical background required is discussed and the natural link to quantum teleportation is established before discussing the nature of Gaussian entanglement swapping. The limitations of Gaussian swapping are introduced, along with the general applications of swapping in the context of to quantum communication and entanglement distribution. In light of this, we briefly summarize a collection of entanglement swapping schemes which incorporate a non-Gaussian ingredient and the benefits of such schemes are noted. Finally, we motivate the need to further study and develop such schemes by highlighting requirements of a continuous-variable repeater.
The study of entanglement between discrete and continuous variables is an important theoretical and experimental topic in quantum information processing, for which entanglement swapping is one of the interesting elements. Entanglement swapping allows two particles without interacting with each other in any way, to form an entangled state by the action of another pair of entangled particles. In this paper, we propose an experimentally feasible scheme to realize deterministic entanglement swapping in the hybrid system with discrete and continuous variables. The process is achieved by preparing two pairs of entangled states, each is formed by a qubit and two quasi-orthogonal coherent state elements of a cavity, performing a Bell-state analysis through nonlocal operations on the continuous variable states of the two cavities, and projecting the two qubits into a maximally entangled state. The present scheme may be applied to other physical systems sustaining such hybrid discrete and continuous forms, providing a typical paradigm for entanglement manipulation through deterministic swapping operations.
A scheme for the entanglement swapping of entangled states with continuous variable is presented, in which the bipartite maximally entangled coherent state serves as the quantum channel.With the help of the idea of teleportation,using beam splitter and phase-shifter,entanglement swapping of tripartite entangled coherent state can be realized.In this scheme,the entanglement swapping is failure only for one measurement process.The failure probability is very small.The detail results show that the probability and the minimum of total average fidelity for successful swapping an arbitrary tripartite entangled coherent state is nearly 1 when the mean number of photons is larger than 2.
Entanglement swapping of two-mode Gaussian states is investigated by use of quantum teleportation protocol of continuous variables. In the entanglement swapping protocol, we take the two-mode squeezed vacuum which is exposed in a thermal environment as a mixed-quantum-channel state and a two-mode standard form Gaussian state as an input state to be teleported. When the input state is pure, we find that the swapped state is inseparable if and only if both the input state and the quantum-channel state are entangled. When the input state is mixed and entangled, we find that the swapped state is inseparable only if the quantum-channel state is sufficiently much entangled. We also notice that the required minimum entanglement in the mixed quantum channel to maintain entanglement in the swapped state strongly depends on the global purity of the input state.
Entanglement swapping, which establishes entanglement between two independent and distant entangled states, is a key element of a quantum repeater in an entanglement-based quantum network. In continuous-variable (CV) entanglement swapping, it is essential to enhance the entanglement of entanglement swapping because it decreases with loss and noise in the quantum channel. Here, we propose a scheme of enhancing entanglement of CV entanglement swapping by a photon subtraction (PS) operation in noisy channels. We apply both one- and two-sided PS operations in CV entanglement swapping through lossy single- and dual-channel transmission schemes, respectively. In the lossy channel, we show that the two-sided PS operation enables one to obtain higher entanglement and longer transmission distance compared to the one-sided PS operation. Furthermore, we show that the two-sided PS operation can enhance the entanglement of the entanglement swapping in the noisy single-channel CV entanglement swapping. Our results provide a feasible solution to enhance entanglement of CV entanglement swapping, and they have potential applications in building quantum repeaters.