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

arXiv:2305.01797 · Physical Review A

Integrated photonic sources of frequency-bin-encoded multipartite entangled states

Milica Banić, John E. Sipe, Marco Liscidini

Published Jan 9, 2024• 10 citations
arXivHTMLPDF

Abstract

We demonstrate that genuine multipartite entangled states can be generated using frequency bin encoding in integrated photonic platforms. We introduce a source of four-photon GHZ states and a source of three-photon W states. We predict generation rates on the order of ${10}^{4}$ Hz for a silicon microring source with milliwatt pump powers. These results, along with the versatility and scalability of integrated structures, identify this as a promising approach for the generation of higher-dimensional and larger entangled states.

DOI
10.1103/physreva.109.013505

Related papers

Photonic multipartite entanglement in discrete variables without arbitrary unitaries

Milica Banić, John E. Sipe, Marco Liscidini

We present an approach for designing sources of postselected multipartite states based on photon-pair sources. Our approach can be applied to arbitrary target states in different encoding schemes and physical platforms. It also allows one to limit the types of components to be used in the device, such that lossy or difficult-to-implement optical elements can be avoided. As an example, we apply this strategy to design a passive integrated source of frequency-bin-encoded high-dimensional GHZ states with a 10-kHz on-chip generation rate for picojoule pump pulses.

arXiv:2409.04250•Physical Review Research•Jan 16, 2025•2 citations

Scalable and efficient source of entangled frequency bins

Marco Liscidini, John E. Sipe

We present a scalable and efficient approach for the generation of frequency-bin encoded qudit states in photonic integrated devices. We exploit a series of coherently pumped resonators, each generating photon pairs in specific frequency bins via spontaneous four-wave mixing. The generated state can be described as a coherent superposition of the states that would describe the pairs generated in each ring separately. As the frequency bin separation is not fixed by the resonator free spectral range, small resonators having large finesse and pair generation rates can be used.

Optics Letters•May 15, 2019•25 citations

Quantum correlations in integrated photonic frequency combs

Laurent Labonté, Adrien Bensemhoun, Dorian Oser +12 more

Integrated photonic platforms provide a powerful route toward scalable and stable quantum light sources. In this presentation, we explore how quantum correlations can be generated, distributed, and characterized in the frequency domain using integrated photonic frequency combs. Relying on Kerr nonlinear microresonators operated below and above threshold, we demonstrate the generation of discrete entangled photon pairs as well as bright multipartite quantum states involving many spectral modes. We show how frequency multiplexing enables both multi-user quantum communication and enhanced data rates, while remaining fully compatible with integrated photonic circuits. Beyond bipartite entanglement, we report direct signatures of genuine multipartite quantum correlations in bright frequency combs. These results highlight integrated photonics as a versatile and scalable platform for multimode quantum technologies in communication, sensing, and metrology.

Integrated Photonics Platforms•May 29, 2026•0 citations

Fully integrated quantum frequency processor on a silicon chip

Sara Congia, Leopold Virot, Elena Rovetta +5 more

Frequency-bin encoding has recently emerged as a powerful approach for photonic quantum information processing, offering high dimensionality, gate-parallelization, and compatibility with existing telecommunication infrastructure. However, its scalable deployment has so far been hindered by the lack of an integrated platform capable of unifying quantum state generation, coherent frequency mixing, and programmable spectral control.\\ Here, we report the first fully integrated quantum frequency processor, monolithically integrating on the same silicon photonic chip a microresonator-based biphoton quantum frequency comb source, a pump-rejection filter, high-speed phase modulators, and a four-channel, line-by-line pulse shaper. We demonstrate key functionalities, such as tunable frequency beamsplitters with success probabilities exceeding $94\%$ and fidelities above $99.9\%$, as well as the ability to synthesize more general single-qubit gates. Finally, we generate and coherently manipulate high-dimensional frequency-bin entangled states entirely on chip, showcasing control over two-photon quantum walks and performing the first on-chip frequency-bin quantum state tomography of a Bell-state with a fidelity of $95.7(3)\%$. By integrating all key functional elements on the same $4\times7\,\textrm{mm}^2$ chip, with the possibility of scaling to a larger number of modes, our work marks an important step toward large-scale frequency-domain photonic processors for both classical and quantum applications.

quant-pharXiv:2602.14240•Nature Communications•Feb 17, 2026•1 citation

A reconfigurable silicon photonics chip for the generation of frequency bin entangled qudits

Massimo Borghi, Noemi Tagliavacche, Federico Andrea Sabattoli +9 more

Quantum optical microcombs in integrated ring resonators generate entangled photon pairs over many spectral modes, and allow the preparation of high dimensional qudit states. Ideally, those sources should be programmable and have a high generation rate, with comb lines tightly spaced for the implementation of efficient qudit gates based on electro-optic frequency mixing. While these requirements cannot all be satisfied by a single resonator device, for which there is a trade-off between high generation rate and tight bin spacing, a promising strategy is the use of multiple resonators, each generating photon pairs in specific frequency bins via spontaneous four-wave mixing. Based on this approach we present a programmable silicon photonics device for the generation of frequency bin entangled qudits, in which bin spacing, qudit dimension, and bipartite quantum state can be reconfigured on-chip. Using resonators with a radius of 22 microns, we achieve a high brightness (MHz/(mW)^2) per comb line with a bin spacing of 15 GHz, and fidelities above 85% with maximally entangled Bell states up to a Hilbert space dimension of sixteen. By individually addressing each spectral mode, we realize states that can not be generated on-chip using a single resonator. We measure the correlation matrices of maximally entangled two-qubit and two-qutrit states on a set of mutually unbiased bases, finding fidelities exceeding 98%, and indicating that the source can find application in high-dimensional secure communication protocols.

arXiv:2301.08475•Jan 20, 2023•0 citations

Toward quantum networking with frequency-bin qudits

Karthik V. Myilswamy, Suparna Seshadri, Hsuan‐Hao Lu +4 more

Quantum networking holds tremendous promise in transforming computation and communication. Entangled-photon sources are critical for quantum repeaters and networking, while photonic integrated circuits are vital for miniaturization and scalability. In this talk, we focus on generating and manipulating frequency-bin entangled states within integrated platforms. We encode quantum information as a coherent superposition of multiple optical frequencies; this approach is favorable due to its amenability to high-dimensional entanglement and compatibility with fiber transmission. We successfully generate and measure the density matrix of biphoton frequency combs from integrated silicon nitride microrings, fully reconstructing the state in an 8 × 8 two-qudit Hilbert space, the highest so far for frequency bins. Moreover, we employ Vernier electro-optic phase modulation methods to perform time-resolved measurements of biphoton correlation functions. Currently, we are exploring bidirectional pumping of microrings to generate indistinguishable entangled pairs in both directions, aiming to demonstrate key networking operations such as entanglement swapping and Greenberger–Horne–Zeilinger state generation in the frequency domain.

Quantum Computing, Communication, and Simulation•Mar 12, 2024•2 citations
We demonstrate that genuine multipartite entangled states can be generated using frequency bin encoding in integrated photonic platforms. We introduce a source of four-photon GHZ states and a source of three-photon W states. We predict generation rates on the order of 104{10}^{4}104 Hz for a silicon microring source with milliwatt pump powers. These results, along with the versatility and scalability of integrated structures, identify this as a promising approach for the generation of higher-dimensional and larger entangled states.
We present an approach for designing sources of postselected multipartite states based on photon-pair sources. Our approach can be applied to arbitrary target states in different encoding schemes and physical platforms. It also allows one to limit the types of components to be used in the device, such that lossy or difficult-to-implement optical elements can be avoided. As an example, we apply this strategy to design a passive integrated source of frequency-bin-encoded high-dimensional GHZ states with a 10-kHz on-chip generation rate for picojoule pump pulses.
We present a scalable and efficient approach for the generation of frequency-bin encoded qudit states in photonic integrated devices. We exploit a series of coherently pumped resonators, each generating photon pairs in specific frequency bins via spontaneous four-wave mixing. The generated state can be described as a coherent superposition of the states that would describe the pairs generated in each ring separately. As the frequency bin separation is not fixed by the resonator free spectral range, small resonators having large finesse and pair generation rates can be used.
Integrated photonic platforms provide a powerful route toward scalable and stable quantum light sources. In this presentation, we explore how quantum correlations can be generated, distributed, and characterized in the frequency domain using integrated photonic frequency combs. Relying on Kerr nonlinear microresonators operated below and above threshold, we demonstrate the generation of discrete entangled photon pairs as well as bright multipartite quantum states involving many spectral modes. We show how frequency multiplexing enables both multi-user quantum communication and enhanced data rates, while remaining fully compatible with integrated photonic circuits. Beyond bipartite entanglement, we report direct signatures of genuine multipartite quantum correlations in bright frequency combs. These results highlight integrated photonics as a versatile and scalable platform for multimode quantum technologies in communication, sensing, and metrology.
Frequency-bin encoding has recently emerged as a powerful approach for photonic quantum information processing, offering high dimensionality, gate-parallelization, and compatibility with existing telecommunication infrastructure. However, its scalable deployment has so far been hindered by the lack of an integrated platform capable of unifying quantum state generation, coherent frequency mixing, and programmable spectral control.\\ Here, we report the first fully integrated quantum frequency processor, monolithically integrating on the same silicon photonic chip a microresonator-based biphoton quantum frequency comb source, a pump-rejection filter, high-speed phase modulators, and a four-channel, line-by-line pulse shaper. We demonstrate key functionalities, such as tunable frequency beamsplitters with success probabilities exceeding 94%94\%94% and fidelities above 99.9%99.9\%99.9%, as well as the ability to synthesize more general single-qubit gates. Finally, we generate and coherently manipulate high-dimensional frequency-bin entangled states entirely on chip, showcasing control over two-photon quantum walks and performing the first on-chip frequency-bin quantum state tomography of a Bell-state with a fidelity of 95.7(3)%95.7(3)\%95.7(3)%. By integrating all key functional elements on the same 4×7 mm24\times7\,\textrm{mm}^24×7mm2 chip, with the possibility of scaling to a larger number of modes, our work marks an important step toward large-scale frequency-domain photonic processors for both classical and quantum applications.
Quantum optical microcombs in integrated ring resonators generate entangled photon pairs over many spectral modes, and allow the preparation of high dimensional qudit states. Ideally, those sources should be programmable and have a high generation rate, with comb lines tightly spaced for the implementation of efficient qudit gates based on electro-optic frequency mixing. While these requirements cannot all be satisfied by a single resonator device, for which there is a trade-off between high generation rate and tight bin spacing, a promising strategy is the use of multiple resonators, each generating photon pairs in specific frequency bins via spontaneous four-wave mixing. Based on this approach we present a programmable silicon photonics device for the generation of frequency bin entangled qudits, in which bin spacing, qudit dimension, and bipartite quantum state can be reconfigured on-chip. Using resonators with a radius of 22 microns, we achieve a high brightness (MHz/(mW)^2) per comb line with a bin spacing of 15 GHz, and fidelities above 85% with maximally entangled Bell states up to a Hilbert space dimension of sixteen. By individually addressing each spectral mode, we realize states that can not be generated on-chip using a single resonator. We measure the correlation matrices of maximally entangled two-qubit and two-qutrit states on a set of mutually unbiased bases, finding fidelities exceeding 98%, and indicating that the source can find application in high-dimensional secure communication protocols.
Quantum networking holds tremendous promise in transforming computation and communication. Entangled-photon sources are critical for quantum repeaters and networking, while photonic integrated circuits are vital for miniaturization and scalability. In this talk, we focus on generating and manipulating frequency-bin entangled states within integrated platforms. We encode quantum information as a coherent superposition of multiple optical frequencies; this approach is favorable due to its amenability to high-dimensional entanglement and compatibility with fiber transmission. We successfully generate and measure the density matrix of biphoton frequency combs from integrated silicon nitride microrings, fully reconstructing the state in an 8 × 8 two-qudit Hilbert space, the highest so far for frequency bins. Moreover, we employ Vernier electro-optic phase modulation methods to perform time-resolved measurements of biphoton correlation functions. Currently, we are exploring bidirectional pumping of microrings to generate indistinguishable entangled pairs in both directions, aiming to demonstrate key networking operations such as entanglement swapping and Greenberger–Horne–Zeilinger state generation in the frequency domain.