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 Modern Optics

Multipartite continuous-variable entanglement in a multi-mode period pumping non-degenerate optical parametric amplifier

Chao Zhao

Published May 26, 2015• 1 citation
Publisher

Abstract

The multipartite continuous-variable (CV) entanglement characteristic of a multi-mode phased-locked period pumping non-degenerate optical parametric amplification system was investigated for the case when finite bandwidth is considered. A continuously modulated pumping with a sinusoidal envelope can produce an improvement in the minimum values of the multipartite CV entanglement. The minimum variances can be described approximately by the linear theory formula 1/(1+μ). We should take a proper bandwidth Δω in order to obtain a long-term entanglement. The larger values of pump parameter μ and particle number N result in long-term entanglement.

DOI
10.1080/09500340.2015.1045434

Related papers

The influence of pump depletion on multipartite continuous-variable entanglement in a frequency non-degenerate parametric amplifier

Chao Zhao, W.H. Tan

The multipartite continuous variable (CV) entanglement characteristic of a frequency non-degenerate optical parametric amplification (FNOPA) system was investigated for the case when pump depletion is considered. The multipartite CV entanglement depends on the pump parameter, μ, the squeezed parameter, r, and particle number, N. Larger values of pump parameter μ and particle number N result in a very small variance, , and a long-term entanglement.

Journal of Modern Optics•Sep 9, 2011•3 citations

Einstein–Podolsky–Rosen entanglement in time-dependent periodic pumping non-degenerate optical parametric amplifier

Chao Zhao, TAN WEI-HAN

The solution of the time-dependent periodic pumping non-degenerate optical parametric amplifier (NOPA) is derived when the pump depletion is considered both above and below thresholds. Based on this solution, the quantum fluctuation calculated shows that a high entanglement and a good squeezing degree of the parametric light beams are achieved near and above thresholds. We adopt two kinds of pump fields: (i) a continuously modulated pump with a sinusoidal envelope; (ii) a sequence of laser pulses with Gaussian envelopes. We analyse the time evolution of continuous variable entanglement by analytical and numerical calculations, and show that the periodic driven pumping also improves the degree of entanglement. The squeezing and Einstein–Podolsky–Rosen (EPR) entanglement by using the two pumping driven functions are investigated from below to above the threshold regions, the tendencies are nearly the same, and the Gaussian driven function is superior to that of the sine driven function, when the maximum squeezing and the minimum variance of quantum fluctuation are considered. In the meantime, the generalization of frequency degenerate OPA to frequency non-degenerated OPA problem is investigated.

Chinese Physics B•Sep 29, 2009•5 citations

The continuous-variable entanglement in a phase-mismatched frequency non-degenerated optical parametric amplifier

Chao Zhao

We present a new analytical solution for Fokker–Planck equation of phase-mismatched frequency non-degenerate optical parametric amplifier (FNOPA). We investigate the squeezing and continuous variable (CV) entanglement characteristic of a FNOPA working at phase-mismatched condition. We numerically calculate the dependence of the CV entanglement on the relative loss parameter ξ and the phase-mismatched parameter η~. The smaller η~ can bring a long-time entanglement. This method can also be applied to multipartite entanglement situation.

Journal of Modern Optics•Jul 8, 2016•2 citations

Multipartite continuous-variable entanglement in nondegenerate optical parametric amplification system

Chao Zhao, Wei Han Tan, Jiang Rong Xu +1 more

A nondegenerate optical parametric amplification (NOPA) system with N modes can be resolved into combinations of N degenerate parametric amplification (DOPA j, j=1–N) systems. Based on the quantum fluctuations, we extend the method of V1 criterion for bipartite entanglement to multipartite entanglement. The entanglement characteristics for N=2–5 are investigated, the variance V1 decreases as a function of interaction time t, the great N brings a very small variance V1.

Journal of the Optical Society of America B•Apr 12, 2011•6 citations

Long-term stable continuous variable entanglement generation in type-II non-degenerate optical parametric amplifier

Long Ma, Hui Guo, Kui Liu +2 more

Long-term stable entanglement is a crucial aspect in the implementation of reliable quantum information processes. However, long-term continuous variable entanglement generation, especially in type-II non-degenerate optical parametric amplifier, has yet to be reported on. Here, we derive the relationship between entanglement and temperature fluctuations in the crystal of a type-II non-degenerate optical parametric amplifier, and propose a novel method for long-term stable entanglement generation by locking the temperature of the crystal. In the experiment, we obtain a 5.4 dB entanglement lasting two hours. The method holds promise in the generation of a truly usable above 10 dB entanglement and brings us closer to continuous-variable quantum information processing.

Optics Express•Nov 15, 2019•4 citations

The tripartite entanglement in a phase-mismatched frequency non-degenerated optical parametric amplifier

Chao Zhao

We present an analytical solution for Fokker–Planck equation of phase-mismatched frequency non-degenerated optical parametric amplifier (FNOPA). We investigate the continuous-variable (CV) tripartite entanglement characteristic of FNOPA working at phase-matched and phase-mismatched condition. From below threshold to above threshold, we numerically calculate the dependence of CV tripartite entanglement on relative loss parameter η and phase-mismatched factor Δω. The larger η and the smaller Δω can bring a good entanglement.

Journal of Modern Optics•Aug 2, 2016•1 citation
The multipartite continuous-variable (CV) entanglement characteristic of a multi-mode phased-locked period pumping non-degenerate optical parametric amplification system was investigated for the case when finite bandwidth is considered. A continuously modulated pumping with a sinusoidal envelope can produce an improvement in the minimum values of the multipartite CV entanglement. The minimum variances can be described approximately by the linear theory formula 1/(1+μ). We should take a proper bandwidth Δω in order to obtain a long-term entanglement. The larger values of pump parameter μ and particle number N result in long-term entanglement.
The solution of the time-dependent periodic pumping non-degenerate optical parametric amplifier (NOPA) is derived when the pump depletion is considered both above and below thresholds. Based on this solution, the quantum fluctuation calculated shows that a high entanglement and a good squeezing degree of the parametric light beams are achieved near and above thresholds. We adopt two kinds of pump fields: (i) a continuously modulated pump with a sinusoidal envelope; (ii) a sequence of laser pulses with Gaussian envelopes. We analyse the time evolution of continuous variable entanglement by analytical and numerical calculations, and show that the periodic driven pumping also improves the degree of entanglement. The squeezing and Einstein–Podolsky–Rosen (EPR) entanglement by using the two pumping driven functions are investigated from below to above the threshold regions, the tendencies are nearly the same, and the Gaussian driven function is superior to that of the sine driven function, when the maximum squeezing and the minimum variance of quantum fluctuation are considered. In the meantime, the generalization of frequency degenerate OPA to frequency non-degenerated OPA problem is investigated.
We present a new analytical solution for Fokker–Planck equation of phase-mismatched frequency non-degenerate optical parametric amplifier (FNOPA). We investigate the squeezing and continuous variable (CV) entanglement characteristic of a FNOPA working at phase-mismatched condition. We numerically calculate the dependence of the CV entanglement on the relative loss parameter ξ and the phase-mismatched parameter η~. The smaller η~ can bring a long-time entanglement. This method can also be applied to multipartite entanglement situation.
Long-term stable entanglement is a crucial aspect in the implementation of reliable quantum information processes. However, long-term continuous variable entanglement generation, especially in type-II non-degenerate optical parametric amplifier, has yet to be reported on. Here, we derive the relationship between entanglement and temperature fluctuations in the crystal of a type-II non-degenerate optical parametric amplifier, and propose a novel method for long-term stable entanglement generation by locking the temperature of the crystal. In the experiment, we obtain a 5.4 dB entanglement lasting two hours. The method holds promise in the generation of a truly usable above 10 dB entanglement and brings us closer to continuous-variable quantum information processing.
We present an analytical solution for Fokker–Planck equation of phase-mismatched frequency non-degenerated optical parametric amplifier (FNOPA). We investigate the continuous-variable (CV) tripartite entanglement characteristic of FNOPA working at phase-matched and phase-mismatched condition. From below threshold to above threshold, we numerically calculate the dependence of CV tripartite entanglement on relative loss parameter η and phase-mismatched factor Δω. The larger η and the smaller Δω can bring a good entanglement.