Cited by 842Quantum Information and CryptographyAdvanced Fiber Laser TechnologiesQuantum optics and atomic interactions

The DOI matches its Crossref record; 39 of the 39 references it cites were found in a registry or an index; none of the 22 sources its claims cite is checked for support yet.

Generation of multiphoton entangled quantum states by means of integrated frequency combs

Open access

Abstract

Entangled frequency combs: The ability to generate optical frequency combs in which the output light is made up of millions of sharp lines precisely spaced apart has been important for optical applications and for fundamental science. Reimer et al. now show that frequency combs can be taken into the quantum regime. They took individual teeth of the combs and quantum-mechanically entangled them to form complex optical states. Because the method is compatible with existing fiber and semiconductor technology, the results demonstrate a possible scalable and practical platform for quantum technologies. Science , this issue p. 1176

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

Integrated Kerr frequency combs in a CMOS-compatible microring resonator generate broadband time-bin entangled photon pairs and four-photon entangled states via spontaneous four-wave mixing. The platform produces high-visibility two-photon entanglement and four-photon interference, with state tomography showing 96% fidelity for two-photon qubits and 64% for four-photon states.

Key findings

  • The microring resonator had a Q-factor of about 240,000, 803 MHz linewidth, and 200 GHz free spectral range, emitting photons across the S, C, and L ITU bands from 1470 to 1620 nm with pair production rates of 0.02–0.04 pairs per pulse.
  • Time-bin entangled qubits were generated across comb resonances; five selected channel pairs showed raw quantum-interference visibilities above 0.824, violating the CHSH/Bell-like inequality, and background-corrected visibilities above 93.2%.
  • Four-photon time-bin entangled states were generated by selecting two signal-idler pairs; at 1.5 mW pump power, a quadruple detection rate of 0.17 Hz was measured, corresponding to a calculated generation rate of 135 kHz, with four-photon interference visibility of 89%.
  • Quantum state tomography gave a two-photon fidelity of 96% and a four-photon fidelity of 64%; after adding 40 km of fiber, the two-photon fidelity was 87%.

Methods

  • The source was a four-port microring resonator in CMOS-compatible high-refractive-index glass, pumped by a 16.8 MHz repetition-rate mode-locked fiber laser filtered to a single ring resonance at 1556.2 nm with 570 ps pulses.
  • Photon pairs were generated by spontaneous four-wave mixing; time-bin entanglement was created by passing the pump through a stabilized unbalanced fiber interferometer with an 11.4 ns delay, producing double pulses with a defined relative phase.
  • Entanglement was characterized by quantum interference measurements with signal and idler interferometers, Bell-like inequality violation, four-photon interference, and quantum state tomography.

Limitations

  • The paper states that the demonstrated multi-photon entangled states are separable, generated as a product of bi-photon Bell states, and that non-separable multi-photon cluster states would require multiple excitation fields or controlled phase gates.
  • The four-photon fidelity of 64% was obtained without compensation for background noise or interferometer imperfections, and system/detection losses were 14.75 dB.
  • The text notes spectral asymmetry from Raman scattering, which could be reduced by cooling the chip, and that further device integration could reduce size and losses; the current setup uses fiber-connected components rather than a single chip.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1126/science.aad8532

Cites

39 of 39 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

0 of 22 cited sources checked · 0 supported · 0 flagged

Show all 24 claims

  • It may state two separate claims as one. 23
  • Probably not a substantial claim. 6
27 of 27
  • The paper relies on this without support.

    The integrated Kerr frequency comb platform is compatible with quantum memory infrastructures.

    “Our method is compatible with contemporary fiber and quantum memory infrastructures, as well as chip-scale semiconductor technology, enabling compact, low-cost, and scalable implementations.”
  • The paper relies on this without support.

    A 5 dB reduction in losses is realistic and a 10 dB reduction is achievable.

    “A very realistic decrease in losses by 5 dB would already increase the four-photon detection rate by a factor of one hundred, while an achievable loss reduction of 10 dB would increase it to the very useful kHz range.”
2 of 2

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Four-photon measurement is assigned two different Fig. 3 panels

    Minor

    The setup description directs readers to Fig. 3E for the four-photon measurements, but the Fig. 3 caption identifies panel F as the four-photon measurement.

1 of 1

Citations

Cites

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Show all 39 references

Research works printed but not linked: 1

  1. SbaihM. A. A.SrourM. K.HamadaM. S.FayadH. M., Lie algebra and representation of SU(4). Electron. J. Theor. Phys. 10, 9–26 (2013).

Cited by

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Items 801–842 of 842

Metadata

Authors
Reimer, C., Kues, M., Roztocki, P., Wetzel, B., Grazioso, F., Little, B. E., Chu, S. T., Johnston, T., Bromberg, Y., Caspani, L., Moss, D. J., & Morandotti, R.
Affiliations
  • Institut National de la Recherche Scientifique (CA)
  • University of Sussex (GB)
  • Chinese Academy of Sciences (CN)
  • City University of Hong Kong (HK)
  • Yale University (US)
  • RMIT University (AU)
  • University of Electronic Science and Technology of China (CN)
Corresponding author
  • Reimer, Christian
  • Kues, Michael
  • Moss, David J.
  • Morandotti, Roberto
Venue
Science
Published
2016-03-11
Volume
351
Issue
6278
Pages
1176-1180
ISSN
  • 0036-8075 (ISSN-L)
  • 1095-9203
OpenAlex
W2316306129
Cited by
841
References
39
Citations by year
2026: 39 · 2025: 64 · 2024: 101 · 2023: 129 · 2022: 99 · 2021: 132 · 2020: 100 · 2019: 60 · 2018: 54 · 2017: 47 · 2016: 16
FWCI
48.51
Type
journal article
Language
en
Open access
Licence
cc-by-nc-nd
Locations
  • Science (publishedVersion)
  • PubMed (publishedVersion)
  • Institutional Repository of Leibniz Universität Hannover (Leibniz Universität Hannover) (submittedVersion, cc-by-nc-nd)
  • Figshare (submittedVersion, cc-by)
  • Institutional Repository of Xi'an Institute of Optics and Fine Mechanics, Chinese Academy of Sciences (Xian Institute of Optics and Precision Mechanics) (submittedVersion, cc-by-nc-sa)
  • IrInSubria (University of Insubria) (submittedVersion)
  • Swinburne figshare (Swinburne University of Technology) (submittedVersion)
  • Leibniz Universität Hannover
Funders
  • Natural Sciences and Engineering Research Council of Canada (NSERC)
  • Australian Research Council
  • FRQNT (Fonds de Recherche du Quebec–Nature et Technologies)
  • Research Executive Agency (REA) (625466)
  • REA (627478)
Topics
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Quantum Information and Cryptography
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Advanced Fiber Laser Technologies
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Quantum optics and atomic interactions
Keywords
multi-photon entanglement, entangled qubits, photon pair generation, integrated photonics, quantum communication, quantum computing, quantum memory

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