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

Optics and Spectroscopy

Experimental characterization of quantum-correlated twin beams and a quantum channel with twin beams

Y. Zhang, K. Hayasaka, K. Kasai

Published Aug 1, 2005• 0 citations
Publisher

Abstract

We report the generation and characterization of quantum-correlated twin beams and their application to a quantum channel. Compared with our previous results, the characterization of twin beams and the quantum channel have been studied with 7.0-dB intensity difference squeezing. The measured inference variance of twin beams is decreased to 0.40 ± 0.02. For the quantum channel, the bit error rate will be 0.035 by using 7.0-dB intensity difference squeezing compared with our previous result of 0.067 by using 4.9-dB intensity difference squeezing.

DOI
10.1134/1.2034601

Related papers

Quantum channel using photon number correlated twin beams

Zhang, Y, Kasai, K, Hayasaka, K

We report quantum communications channel using photon number correlated twin beams. The twin beams are generated from a nondegenerate optical parametric oscillator, and the photon number difference is used to encode the signal. The bit error rate of our system will be 0.067 by using the twin beams comparing with 0.217 by using the coherent state as the signal carrier.

•Jan 8, 2004•13 citations

Quantum channel using photon number correlated twin beams

Yun Zhang, Katsuyuki Kasai, Kazuhiro Hayasaka

We report quantum communications channel using photon number correlated twin beams. The twin beams are generated from a nondegenerate optical parametric oscillator, and the photon number difference is used to encode the signal. The bit error rate of our system will be 0.067 by using the twin beams comparing with 0.217 by using the coherent state as the signal carrier.

arXiv:quant-ph/0401033•Optics Express•Dec 29, 2003•16 citations

Generating quantum correlated twin beams by four-wave mixing in hot cesium vapor

Rong Ma, Wei Liu, Zhongzhong Qin +2 more

Using a nondegenerate four-wave mixing process based on a double-$\mathrm{\ensuremath{\Lambda}}$ scheme in hot cesium vapor, we generate quantum correlated twin beams with a maximum intensity-difference squeezing of 6.5 dB. The substantially improved squeezing can be mainly attributed to very good frequency and phase-difference stability between the pump and probe beams in our experiment. Intensity-difference squeezing can be observed within a wide experimental parameter range, which guarantees its robust generation. Since this scheme produces multi-spatial-mode twin beams at the Cs ${D}_{1}$ line, it is of interest for experiments involving quantum imaging and coherent interfaces between atomic and solid-state systems.

arXiv:1710.06706•Physical Review A•Oct 17, 2017•24 citations

Generation of Quantum-Correlated Twin Beams and Its Application

Katsuyuki Kasai

The signal and idler beams from a non-degenerate, above threshold, optical parametric oscillator have a strong quantum correlation, which are called twin beams. This correlation arises from the simultaneous generation of the signal and idler photons in the form of twin pairs of photons through the parametric down conversion, and the generated twin beams have exactly the same photon statistics. As a result, the fluctuations on the difference between the intensities of the twin beams are reduced with respect to the shot noise limit, that is, intensity-difference squeezing. We give a comprehensive overview of the generation of twin beams using the optical parametric oscillator, and the applications exploiting the quantum correlation of twin beams are presented.

The Review of Laser Engineering•Jan 1, 2003•0 citations

Experimental investigation of the intensity fluctuation joint probability and conditional distributions of the twin-beam quantum state

Yun Zhang, Katsuyuki Kasai, Masayoshi Watanabe

We give the intensity fluctuation joint probability of the twin-beam quantum state, which was generated with an optical parametric oscillator operating above threshold. Then we present what to our knowledge is the first measurement of the intensity fluctuation conditional probability distributions of twin beams. The measured inference variance of twin beams 0.62+/-0.02, which is less than the standard quantum limit of unity, indicates inference with a precision better than that of separable states. The measured photocurrent variance exhibits a quantum correlation of as much as -4.9+/-0.2 dB between the signal and the idler.

Optics Express•Jan 13, 2003•14 citations

Conditional transfer of quantum correlation in the intensity of twin beams

Yun Zhang, Kazuhiro Hayasaka, Katsuyuki Kasai

A conditional protocol of transferring quantum correlations in a continuous variable regime was experimentally demonstrated. The quantum correlation in two pairs of twin beams, each characterized by intensity-difference squeezing of $7.0\ifmmode\pm\else\textpm\fi{}0.3\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$, was transferred to two initially independent idler beams. The quantum-correlation transfer resulted in intensity-difference squeezing of $4.0\ifmmode\pm\else\textpm\fi{}0.2\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$ between two idler beams. The dependence of the preparation probability and transfer fidelity on the selection bandwidth was also studied.

arXiv:quant-ph/0504032•Physical Review A•Jun 30, 2005•26 citations
We report the generation and characterization of quantum-correlated twin beams and their application to a quantum channel. Compared with our previous results, the characterization of twin beams and the quantum channel have been studied with 7.0-dB intensity difference squeezing. The measured inference variance of twin beams is decreased to 0.40 ± 0.02. For the quantum channel, the bit error rate will be 0.035 by using 7.0-dB intensity difference squeezing compared with our previous result of 0.067 by using 4.9-dB intensity difference squeezing.
Using a nondegenerate four-wave mixing process based on a double-$\mathrm{\ensuremath{\Lambda}}$ scheme in hot cesium vapor, we generate quantum correlated twin beams with a maximum intensity-difference squeezing of 6.5 dB. The substantially improved squeezing can be mainly attributed to very good frequency and phase-difference stability between the pump and probe beams in our experiment. Intensity-difference squeezing can be observed within a wide experimental parameter range, which guarantees its robust generation. Since this scheme produces multi-spatial-mode twin beams at the Cs D1{D}_{1}D1​ line, it is of interest for experiments involving quantum imaging and coherent interfaces between atomic and solid-state systems.
The signal and idler beams from a non-degenerate, above threshold, optical parametric oscillator have a strong quantum correlation, which are called twin beams. This correlation arises from the simultaneous generation of the signal and idler photons in the form of twin pairs of photons through the parametric down conversion, and the generated twin beams have exactly the same photon statistics. As a result, the fluctuations on the difference between the intensities of the twin beams are reduced with respect to the shot noise limit, that is, intensity-difference squeezing. We give a comprehensive overview of the generation of twin beams using the optical parametric oscillator, and the applications exploiting the quantum correlation of twin beams are presented.
We give the intensity fluctuation joint probability of the twin-beam quantum state, which was generated with an optical parametric oscillator operating above threshold. Then we present what to our knowledge is the first measurement of the intensity fluctuation conditional probability distributions of twin beams. The measured inference variance of twin beams 0.62+/-0.02, which is less than the standard quantum limit of unity, indicates inference with a precision better than that of separable states. The measured photocurrent variance exhibits a quantum correlation of as much as -4.9+/-0.2 dB between the signal and the idler.
A conditional protocol of transferring quantum correlations in a continuous variable regime was experimentally demonstrated. The quantum correlation in two pairs of twin beams, each characterized by intensity-difference squeezing of $7.0\ifmmode\pm\else\textpm\fi{}0.3\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$, was transferred to two initially independent idler beams. The quantum-correlation transfer resulted in intensity-difference squeezing of $4.0\ifmmode\pm\else\textpm\fi{}0.2\phantom{\rule{0.3em}{0ex}}\mathrm{dB}$ between two idler beams. The dependence of the preparation probability and transfer fidelity on the selection bandwidth was also studied.