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

International Journal of Quantum Information

DECOHERENCE OF GAUSSIAN AND NONGAUSSIAN PHOTON-NUMBER ENTANGLED STATES IN A NOISY CHANNEL

Michele Allegra, Paolo Giorda, Matteo G. A. Paris

Published Jan 1, 2011• 2 citations
Publisher

Abstract

We consider photon-number entangled states (PNES) and study the degradation of their entanglement in a noisy channel, using different separability criteria and a recently proposed measure of nonGaussianity as key tools. Upon comparing Gaussian and nonGaussian states within the class, we collect some evidence that Gaussian states are maximally robust against noise, i.e. the complete loss of entanglement occurs in maximal time. However, the gap with respect to nonGaussian states is negligible for sufficiently high energy of the states.

DOI
10.1142/s0219749911007009

Related papers

Robustness of Gaussian Entanglement

Michele Allegra, Paolo Giorda, Matteo G. A. Paris

We address the degradation of continuous variable (CV) entanglement in a noisy channel focusing on the set of photon-number entangled states. We exploit several separability criteria and compare the resulting separation times with the value of non-Gaussianity at any time, thus showing that in the low-temperature regime: i) non-Gaussianity is a bound for the relative entropy of entanglement and ii) Simon' criterion provides a reliable estimate of the separation time also for nonGaussian states. We provide several evidences supporting the conjecture that Gaussian entanglement is the most robust against noise, i.e. it survives longer than nonGaussian one, and that this may be a general feature for CV systems in Markovian channels.

•Mar 17, 2010•0 citations

Role of Initial Entanglement and Non-Gaussianity in the Decoherence of Photon-Number Entangled States Evolving in a Noisy Channel

Michele Allegra, Paolo Giorda, Matteo G. A. Paris

We address the degradation of continuous variable (CV) entanglement in a noisy channel focusing on the set of photon-number entangled states. We exploit several separability criteria and compare the resulting separation times with the value of non-Gaussianity at any time, thus showing that in the low-temperature regime: (i) non-Gaussianity is a bound for the relative entropy of entanglement and (ii) Simon's criterion provides a reliable estimate of the separation time also for non-Gaussian states. We provide several evidences supporting the conjecture that Gaussian entanglement is the most robust against noise, i.e., it survives longer than a non-Gaussian one, and that this may be a general feature for CV systems in Markovian channels.

arXiv:1003.3331•Physical Review Letters•Sep 1, 2010•44 citations

Fock States in Additive Gaussian Noise Channels: Analytical and Numerical Considerations

Emad Zinoghli, Jawad A. Salehi

ABSTRACT In this paper, we study the effects of additive Gaussian noise on Fock states. We put forth a simple analytical formula for the resulting output states. Additionally, we conduct numerical analysis into several key properties of noisy Fock states, including their purity, nonclassicality and non‐Gaussianness, with respect to the noise parameter. Finally, we examine the impact of noise on entangled N00N states, focusing on its entanglement‐breaking effects, which we quantify using the logarithmic negativity measure. Regarding purity, we observe that for a fixed noise level, the purity of a noisy Fock state decreases as the number of photons increases. In terms of non‐Gaussianity, we show that at any given noise level, higher Fock states exhibit higher non‐Gaussianity compared to lower ones. Although all noisy Fock states eventually lose their nonclassical characteristics under sufficient noise, higher Fock states exhibit more pronounced nonclassical features in low‐noise conditions, whereas lower Fock states show greater nonclassicality in high‐noise environments. We quantitatively show that the state is the most robust against additive Gaussian noise among the N00N states.

IET Quantum Communication•Jan 1, 2025•1 citation

Robustness of quantum nonclassicality and non-Gaussianity of single-photon states in attenuating channels

Lukáš Lachman, Radim Filip

We ab initio derive quantum nonclassicality and non-Gaussianity criteria for realistic single-photon sources and discuss the robustness of these quantum features in attenuating quantum channel. The derivation based only on assumptions about the structure of the detector is performed for standard autocorrelation measurement with single-photon detectors. Using both the criteria, we compare the robustness of quantum features of realistic single-photon states with the Poissonian and thermal background noise and discuss a difference between the impact of the multimode structure of thermal noise and truly Poissonian noise.

Physical Review A•Dec 23, 2013•24 citations

Non-Gaussianity and security of entanglement-based QKD

Mariia Gumberidze, Vladyslav C. Usenko

We theoretically analyse the relation between non-Gaussianity and security of entanglement-based quantum key distribution (QKD) protocols, namely device-independent (DI) and entanglement-based BB$84$. A similar analysis has already been made for prepare-and-measure (P\&M) protocols \cite{Lasota2017}. In addition, we consider imperfect detection with dark counts and limited efficiency. We assume a perfect source of entangled Bell states as produced by quantum-dot type sources, depolarisation in the channel and different noise statistics, namely thermal and Poissonian. We consider single-photon avalanche photodiodes (SPAD) and photon number resolving detectors (PNRD) and use their respective criteria for non-Gaussianity. The results show cross-regions for both security and non-Gaussianity, hence, the possibility to conclude about the suitability of a given channel for secret key distribution. Our results can be useful as a pre-check for the implementation of QKD protocols.

quant-pharXiv:2511.01761•Nov 4, 2025•0 citations

Experimental demonstration of robustness of Gaussian quantum coherence

Haijun Kang, Dongmei Han, Na Wang +3 more

Besides quantum entanglement and steering, quantum coherence has also been identified as a useful quantum resource in quantum information. It is important to investigate the evolution of quantum coherence in practical quantum channels. In this paper, we experimentally quantify the quantum coherence of a squeezed state and a Gaussian Einstein-Podolsky-Rosen (EPR) entangled state transmitted in Gaussian thermal noise channel, respectively. By reconstructing the covariance matrix of the transmitted states, quantum coherence of these Gaussian states is quantified by calculating the relative entropy. We show that quantum coherence of the squeezed state and the Gaussian EPR entangled state is robust against loss and noise in a quantum channel, which is different from the properties of squeezing and Gaussian entanglement. Our experimental results pave the way for application of Gaussian quantum coherence in lossy and noisy environments.

arXiv:2105.11286•May 24, 2021•1 citation
We consider photon-number entangled states (PNES) and study the degradation of their entanglement in a noisy channel, using different separability criteria and a recently proposed measure of nonGaussianity as key tools. Upon comparing Gaussian and nonGaussian states within the class, we collect some evidence that Gaussian states are maximally robust against noise, i.e. the complete loss of entanglement occurs in maximal time. However, the gap with respect to nonGaussian states is negligible for sufficiently high energy of the states.
We address the degradation of continuous variable (CV) entanglement in a noisy channel focusing on the set of photon-number entangled states. We exploit several separability criteria and compare the resulting separation times with the value of non-Gaussianity at any time, thus showing that in the low-temperature regime: i) non-Gaussianity is a bound for the relative entropy of entanglement and ii) Simon' criterion provides a reliable estimate of the separation time also for nonGaussian states. We provide several evidences supporting the conjecture that Gaussian entanglement is the most robust against noise, i.e. it survives longer than nonGaussian one, and that this may be a general feature for CV systems in Markovian channels.
We address the degradation of continuous variable (CV) entanglement in a noisy channel focusing on the set of photon-number entangled states. We exploit several separability criteria and compare the resulting separation times with the value of non-Gaussianity at any time, thus showing that in the low-temperature regime: (i) non-Gaussianity is a bound for the relative entropy of entanglement and (ii) Simon's criterion provides a reliable estimate of the separation time also for non-Gaussian states. We provide several evidences supporting the conjecture that Gaussian entanglement is the most robust against noise, i.e., it survives longer than a non-Gaussian one, and that this may be a general feature for CV systems in Markovian channels.
ABSTRACT In this paper, we study the effects of additive Gaussian noise on Fock states. We put forth a simple analytical formula for the resulting output states. Additionally, we conduct numerical analysis into several key properties of noisy Fock states, including their purity, nonclassicality and non‐Gaussianness, with respect to the noise parameter. Finally, we examine the impact of noise on entangled N00N states, focusing on its entanglement‐breaking effects, which we quantify using the logarithmic negativity measure. Regarding purity, we observe that for a fixed noise level, the purity of a noisy Fock state decreases as the number of photons increases. In terms of non‐Gaussianity, we show that at any given noise level, higher Fock states exhibit higher non‐Gaussianity compared to lower ones. Although all noisy Fock states eventually lose their nonclassical characteristics under sufficient noise, higher Fock states exhibit more pronounced nonclassical features in low‐noise conditions, whereas lower Fock states show greater nonclassicality in high‐noise environments. We quantitatively show that the state is the most robust against additive Gaussian noise among the N00N states.
We ab initio derive quantum nonclassicality and non-Gaussianity criteria for realistic single-photon sources and discuss the robustness of these quantum features in attenuating quantum channel. The derivation based only on assumptions about the structure of the detector is performed for standard autocorrelation measurement with single-photon detectors. Using both the criteria, we compare the robustness of quantum features of realistic single-photon states with the Poissonian and thermal background noise and discuss a difference between the impact of the multimode structure of thermal noise and truly Poissonian noise.
We theoretically analyse the relation between non-Gaussianity and security of entanglement-based quantum key distribution (QKD) protocols, namely device-independent (DI) and entanglement-based BB848484. A similar analysis has already been made for prepare-and-measure (P\&M) protocols \cite{Lasota2017}. In addition, we consider imperfect detection with dark counts and limited efficiency. We assume a perfect source of entangled Bell states as produced by quantum-dot type sources, depolarisation in the channel and different noise statistics, namely thermal and Poissonian. We consider single-photon avalanche photodiodes (SPAD) and photon number resolving detectors (PNRD) and use their respective criteria for non-Gaussianity. The results show cross-regions for both security and non-Gaussianity, hence, the possibility to conclude about the suitability of a given channel for secret key distribution. Our results can be useful as a pre-check for the implementation of QKD protocols.
Besides quantum entanglement and steering, quantum coherence has also been identified as a useful quantum resource in quantum information. It is important to investigate the evolution of quantum coherence in practical quantum channels. In this paper, we experimentally quantify the quantum coherence of a squeezed state and a Gaussian Einstein-Podolsky-Rosen (EPR) entangled state transmitted in Gaussian thermal noise channel, respectively. By reconstructing the covariance matrix of the transmitted states, quantum coherence of these Gaussian states is quantified by calculating the relative entropy. We show that quantum coherence of the squeezed state and the Gaussian EPR entangled state is robust against loss and noise in a quantum channel, which is different from the properties of squeezing and Gaussian entanglement. Our experimental results pave the way for application of Gaussian quantum coherence in lossy and noisy environments.