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 the Optical Society of America B

Roles of thermal noise and detector efficiency in distillation of continuous variable entanglement state

ShengLi Zhang, Yuli Dong, Jianhong Shi, Xu‐Bo Zou, Guang‐Can Guo

Published Sep 24, 2013• 3 citations
Publisher

Abstract

We address the degradation of continuous variable (CV) entanglement distillation in the presence of thermal environment and nonunity detecting efficiency. We explore the logarithmic negativity as a criteria and compare the output entanglement between the schemes of single-photon subtraction (PS) and two-PS. The probability of success is also investigated. We show that compared with detector efficiency, thermal noise plays a more dominant role in Gaussian entanglement distillation. Our results shed more light on the noise mechanism that influences realistic CV entanglement distillation and is of experimental relevance in developing a more efficient entanglement distillation scheme.

DOI
10.1364/josab.30.002704

Related papers

Continuous-variable-entanglement distillation with photon addition

ShengLi Zhang, YuLi Dong, Xu‐Bo Zou +2 more

Photon subtraction (PS), due to its feasibility in physical implementation, has been widely utilized in Gaussian entanglement distillation. However, in this paper, we will show that photon addition (PA) can be employed to provide an additional enhancement in both the quality of distilled entanglement and the success probability if the input state is a weak two-mode squeezed vacuum state. Moreover, compared with biside PS, the distillation probability gains a $O(\frac{1}{{\ensuremath{\lambda}}^{2}})$ improvement, which increases rapidly when $\ensuremath{\lambda}\ensuremath{\ll}1$. Our PA-based scheme is obtained first by single-photon injection and later by vacuum state projection. The performance of PA in the presence of both an approximated single photon and amplitude-damping noise has been analyzed. Our result sheds more light on the indispensable non-Gaussian ingredients in Gaussian-state distillation and could be of great use in developing more efficient distillation schemes. Finally, the sensitivity of the PA scheme to inefficient photon detection has also been investigated.

Physical Review A•Sep 27, 2013•38 citations

Entanglement distillation for continuous variables in a thermal environment: Effectiveness of a non-Gaussian operation

Jaehak Lee, Hyunchul Nha

We study the task of distilling entanglement by a coherent superposition operation $t\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}+r{\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}}^{\ifmmode\dagger\else\textdagger\fi{}}$ applied to a continuous-variable state under a thermal noise. In particular, we compare the performances of two different strategies; i.e., the non-Gaussian operation $t\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}+r{\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}}^{\ifmmode\dagger\else\textdagger\fi{}}$ is applied before or after the noisy Gaussian channel. This is closely related to a fundamental problem of whether Gaussian or non-Gaussian entanglement can be more robust under a noisy channel and also provides a useful insight into the practical implementation of entanglement distribution for a long-distance quantum communication. We specifically look into two entanglement characteristics, the logarithmic negativity as a measure of entanglement and the teleportation fidelity as a usefulness of entanglement, for each distilled state. We find that the non-Gaussian operation after (before) the thermal noise becomes more effective in the low- (high-) temperature regime.

arXiv:1304.0186•Physical Review A•Mar 7, 2013•29 citations

Distillation of phase-damped continuous-variable entanglement with photon subtraction

ShengLi Zhang, Jianhong Shi, Chenhui Jin +3 more

Photon subtraction (PS) is a widely used technique in the distillation of noise-damped continuous-variable Gaussian entangled states. In the literature, all distillation schemes with the PS technique are restricted to pure Gaussian entanglement or amplitude-damped entanglement, and it is not clear whether PS is applicable in overcoming the phase noise or even more general noise. In this paper, we show that the PS technique is versatile and can still be used to distill entanglement that is subject to phase noise and simultaneous phase and amplitude noise.

Journal of the Optical Society of America B•Jun 21, 2013•4 citations

$O(\sqrt\eta)$ efficiency entanglement distillation with one-time photon subtraction over near-zero transmittance bosonic channel

ShengLi Zhang

Entanglement distillation is an efficient method to retrieve high-quality entanglement from a large number of noise-damped entanglement states. Many investigations on continuous variable entanglement distillation have focused on low-loss or medium-loss channels. Herein, we primarily study entanglement distillation in extremely lossy (total channel transmittance η ≪ 1 ) or even near-zero transmittance ( η ≈ 0 ) channels. In particular, we analyze the manner in which entanglement and success probability decrease as η → 0 . The performances of conventional biside photon subtraction and one-time photon subtraction on two optical modes separated by L km are investigated. The motivation for our study includes the recent advancements in twin-field quantum key distribution, wherein single-photon detection is sufficient to provide a useful private key. In the same vein, we propose an entanglement distillation scheme with an efficiency of O ( η ) using one-time photon subtraction and weak coherent state injection. Thus, our proposed scheme provides a method for distilling extremely damped entanglement states for continuous variable quantum information processing.

Journal of the Optical Society of America B•Dec 12, 2019•1 citation

Multipartite continuous-variable entanglement distillation using local squeezing and only one photon-subtraction operation

Yang, Song, Xu‐Bo Zou, ShengLi Zhang +3 more

In this paper, we study entanglement distillation of multipartite continuous-variable Gaussian entangled states. Following Opatrný \emph{et al.}'s photon subtraction (PS) scheme, the probability of successful distillation decreases exponentially with the number of parties $N$. However, here, we shall propose an entanglement distillation scheme whose success probability scales as a constant with $N$. Our protocol employs several local squeezers, but it requires only a single PS operation. Using the logarithmic negativity as a measure of entanglement, we find that both the success probability and the distilled entanglement can be improved at the same time. Moreover, an $N$-mode transfer theorem (transferring states from phase space to Hilbert space) is presented.

arXiv:1106.1536•Jun 8, 2011•2 citations

Entanglement properties of a measurement-based entanglement distillation experiment

Hao Jeng, Spyros Tserkis, Jing Yan Haw +5 more

Measures of entanglement can be employed for the analysis of numerous quantum information protocols. Due to computational convenience, logarithmic negativity is often the choice in the case of continuous-variable systems. In this work, we analyze a continuous-variable measurement-based entanglement distillation experiment using a collection of entanglement measures. This includes logarithmic negativity, entanglement of formation, distillable entanglement, relative entropy of entanglement, and squashed entanglement. By considering the distilled entanglement as a function of the success probability of the distillation protocol, we show that the logarithmic negativity surpasses the bound on deterministic entanglement distribution at a relatively large probability of success. This is in contrast to the other measures which would only be able to do so at much lower probabilities, hence demonstrating that logarithmic negativity alone is inadequate for assessing the performance of the distillation protocol. In addition to this result, we also observed an increase in the distillable entanglement by making use of upper and lower bounds to estimate this quantity. We thus demonstrate the utility of these theoretical tools in an experimental setting.

arXiv:1811.10822•Physical Review A•Apr 1, 2019•6 citations
We address the degradation of continuous variable (CV) entanglement distillation in the presence of thermal environment and nonunity detecting efficiency. We explore the logarithmic negativity as a criteria and compare the output entanglement between the schemes of single-photon subtraction (PS) and two-PS. The probability of success is also investigated. We show that compared with detector efficiency, thermal noise plays a more dominant role in Gaussian entanglement distillation. Our results shed more light on the noise mechanism that influences realistic CV entanglement distillation and is of experimental relevance in developing a more efficient entanglement distillation scheme.
Photon subtraction (PS), due to its feasibility in physical implementation, has been widely utilized in Gaussian entanglement distillation. However, in this paper, we will show that photon addition (PA) can be employed to provide an additional enhancement in both the quality of distilled entanglement and the success probability if the input state is a weak two-mode squeezed vacuum state. Moreover, compared with biside PS, the distillation probability gains a $O(\frac{1}{{\ensuremath{\lambda}}^{2}})$ improvement, which increases rapidly when $\ensuremath{\lambda}\ensuremath{\ll}1$. Our PA-based scheme is obtained first by single-photon injection and later by vacuum state projection. The performance of PA in the presence of both an approximated single photon and amplitude-damping noise has been analyzed. Our result sheds more light on the indispensable non-Gaussian ingredients in Gaussian-state distillation and could be of great use in developing more efficient distillation schemes. Finally, the sensitivity of the PA scheme to inefficient photon detection has also been investigated.
We study the task of distilling entanglement by a coherent superposition operation $t\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}+r{\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}}^{\ifmmode\dagger\else\textdagger\fi{}}$ applied to a continuous-variable state under a thermal noise. In particular, we compare the performances of two different strategies; i.e., the non-Gaussian operation $t\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}+r{\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}}^{\ifmmode\dagger\else\textdagger\fi{}}$ is applied before or after the noisy Gaussian channel. This is closely related to a fundamental problem of whether Gaussian or non-Gaussian entanglement can be more robust under a noisy channel and also provides a useful insight into the practical implementation of entanglement distribution for a long-distance quantum communication. We specifically look into two entanglement characteristics, the logarithmic negativity as a measure of entanglement and the teleportation fidelity as a usefulness of entanglement, for each distilled state. We find that the non-Gaussian operation after (before) the thermal noise becomes more effective in the low- (high-) temperature regime.
Photon subtraction (PS) is a widely used technique in the distillation of noise-damped continuous-variable Gaussian entangled states. In the literature, all distillation schemes with the PS technique are restricted to pure Gaussian entanglement or amplitude-damped entanglement, and it is not clear whether PS is applicable in overcoming the phase noise or even more general noise. In this paper, we show that the PS technique is versatile and can still be used to distill entanglement that is subject to phase noise and simultaneous phase and amplitude noise.
O(η)O(\sqrt\eta)O(η​) efficiency entanglement distillation with one-time photon subtraction over near-zero transmittance bosonic channel
Entanglement distillation is an efficient method to retrieve high-quality entanglement from a large number of noise-damped entanglement states. Many investigations on continuous variable entanglement distillation have focused on low-loss or medium-loss channels. Herein, we primarily study entanglement distillation in extremely lossy (total channel transmittance η ≪ 1 ) or even near-zero transmittance ( η ≈ 0 ) channels. In particular, we analyze the manner in which entanglement and success probability decrease as η → 0 . The performances of conventional biside photon subtraction and one-time photon subtraction on two optical modes separated by L km are investigated. The motivation for our study includes the recent advancements in twin-field quantum key distribution, wherein single-photon detection is sufficient to provide a useful private key. In the same vein, we propose an entanglement distillation scheme with an efficiency of O ( η ) using one-time photon subtraction and weak coherent state injection. Thus, our proposed scheme provides a method for distilling extremely damped entanglement states for continuous variable quantum information processing.
In this paper, we study entanglement distillation of multipartite continuous-variable Gaussian entangled states. Following Opatrný \emph{et al.}'s photon subtraction (PS) scheme, the probability of successful distillation decreases exponentially with the number of parties NNN. However, here, we shall propose an entanglement distillation scheme whose success probability scales as a constant with NNN. Our protocol employs several local squeezers, but it requires only a single PS operation. Using the logarithmic negativity as a measure of entanglement, we find that both the success probability and the distilled entanglement can be improved at the same time. Moreover, an NNN-mode transfer theorem (transferring states from phase space to Hilbert space) is presented.
Measures of entanglement can be employed for the analysis of numerous quantum information protocols. Due to computational convenience, logarithmic negativity is often the choice in the case of continuous-variable systems. In this work, we analyze a continuous-variable measurement-based entanglement distillation experiment using a collection of entanglement measures. This includes logarithmic negativity, entanglement of formation, distillable entanglement, relative entropy of entanglement, and squashed entanglement. By considering the distilled entanglement as a function of the success probability of the distillation protocol, we show that the logarithmic negativity surpasses the bound on deterministic entanglement distribution at a relatively large probability of success. This is in contrast to the other measures which would only be able to do so at much lower probabilities, hence demonstrating that logarithmic negativity alone is inadequate for assessing the performance of the distillation protocol. In addition to this result, we also observed an increase in the distillable entanglement by making use of upper and lower bounds to estimate this quantity. We thus demonstrate the utility of these theoretical tools in an experimental setting.