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

Light Science & Applications

Transmission of multi-level time-bin encoded cluster states over 29 km of partially deployed optical fiber

Philip Rübeling, Robert Johanning, Jan Heine, Oleksandr V. Marchukov, Michael Kues

Published Sep 30, 2026• 0 citations
Publisher

Abstract

The next generation of telecommunication networks will rely on the distribution of complex quantum resources to enable secure and transformative information processing, utilizing entanglement and superposition. Cluster states-multi-qubit entangled states that retain entanglement under local measurements-are the central resource for measurement-based quantum information processing and compelling for quantum networking applications including blind quantum computing and quantum key agreement. However, transmitting cluster states over optical fiber has remained elusive with previous approaches, as losses scale exponentially with the number of photons. Here, we report the first transmission of a four-qubit cluster state to two parties over a partially deployed single-mode fiber link. The qubits of this state are encoded in two photons with multi-level time-bins. We directly generate the cluster state by exploiting coherent control of a parametric generation process, rendering a resource-intensive controlled-phase gate obsolete. To enable processing of this state, we introduce beam splitting for time-bins via chirped pulse modulation-a novel, reconfigurable Fourier-domain pulse shaping technique. We certify genuine multi-qubit entanglement and demonstrate one-way computing primitives on the transmitted cluster state. Our approach achieves the transmission of cluster states over optical fiber, establishing complex quantum resources fully compatible with telecommunication infrastructure.

DOI
10.1038/s41377-026-02465-5

Related papers

Fiber transmission of cluster states via multi-level time-bin encoding

Philip Rübeling, Robert Johanning, Jan Heine +2 more

The next generation of telecommunication networks will rely on the transmission of complex quantum states to enable secure and transformative information processing, utilizing entanglement and superposition. Cluster states - multipartite entangled states that retain entanglement under local measurements - are a vital resource for quantum networking applications such as blind photonic quantum computing, quantum state teleportation and all-photonic quantum repeaters. However, the transmission of cluster states over optical fiber has remained elusive with previous approaches. Here, we demonstrate the first transmission of a four-qubit cluster state over 25 km of single-mode fiber by using a two-photon multi-level time-bin encoding. We directly generate the state by exploiting coherent control of a parametric generation process, rendering a resource-intensive controlled-phase gate obsolete. To enable efficient and reconfigurable projective measurements on the multi-level time-bin encoded state, we introduce chirped-pulse modulation and implement the first time-bin beam splitter, allowing us to certify genuine multipartite entanglement and to demonstrate one-way computing operations. Our approach enables the transmission of complex quantum states over long-distance fibers, permitting the implementation of multipartite protocols and laying the foundation for large-scale quantum resource networks.

arXiv:2507.01497•Jul 2, 2025•0 citations

Long-Range Transmission of Cluster States over 25 km of Optical Single-Mode Fiber via Multi-Level Time-Bin Encoding

Robert Johanning, Philip Rübeling, Jan Heine +2 more

We demonstrate the transmission of a cluster state over 25 km fiber using multi-level time-bin encoding and chirped pulse modulation. Our work paves the way to multipartite entangled long-distance quantum networking and distributed photonic computing.

Frontiers in Optics•Jan 1, 2025•0 citations

On-chip Generation, Coherent Control and Processing of Complex Entangled Photon States

Stefania Sciara, Raman Kashyap, Alfonso Carmelo Cino +15 more

We demonstrate the on-chip generation of time-bin entangled two- and multi-photon qubit states, as well as high-dimensional frequency-entangled photon pairs. Combining time and frequency entanglement, we generate high-dimensional optical cluster states and implement proof-of-concept high-dimensional one-way quantum computing. This, by using standard, fiber-based telecommunication components.

IEEE/LEOS Summer Topical Meetings•Jul 1, 2019•0 citations

Kerr Combs and Telecommunications Components for the Generation and High-Dimensional Quantum Processing of d-Level Cluster States

Piotr Roztocki, Christian Reimer, Stefania Sciara +15 more

Large and complex optical quantum states are a key resource for fundamental science and applications such as quantum communications, information processing, and metrology. In this context, cluster states are a particularly important class because they enable the realization of universal quantum computers by means of the so-called `one-way' scheme, where processing operations are performed through measurements on the state. While two-level (i.e. qubit) cluster states have been realized thus far, further boosting this computational resource by increasing the number of particles comes at the price of significantly reduced coherence time and detection rates, as well as increased sensitivity to noise. In contrast, the realization of d-level (with d > 2) cluster states offers the possibility to increase quantum resources without changing the number of particles, enables the implementation of efficient computational protocols, as well as coincides with a reduction in the noise sensitivity of the states. Here, we experimentally realize, characterize, and perform one-way processing operations on three-level, four-partite cluster states formed by two photons in the time and frequency domain. We make use of a unique approach based on integrated photonic chips and optical fiber communications components, enabling scalable, deterministic new functionalities.

International Conference on Transparent Optical Networks•Jul 1, 2019•0 citations

Fully controllable time-bin entangled states distributed over 100-km single-mode fibers

Jinwoo Kim, Jiho Park, Guhwan Kim +7 more

Quantum networks that can perform user-defined protocols beyond quantum key distribution will require fully controllable entangled quantum states. To expand the available space of generated time-bin entangled states, we demonstrate a time-bin entangled photon source that produces qubit states $|{\psi}\rangle = \alpha |{00}\rangle + \beta |{11}\rangle $ with fully controllable phase and amplitudes. Eight different two-photon states have been selected and prepared from arbitrary states on the reduced two-qubit Bloch sphere. The photon pairs encoded in the time-bin scheme were generated at 2.4 MHz with a visibility of $V = 0.9475 \pm 0.0016$ , with a violation of the CHSH Bell’s inequality by 197 standard deviations. After entanglement distribution over 100 km of single-mode fibers, we obtained a visibility of $V = 0.9541 \pm 0.0113$ with a violation of the CHSH Bell’s inequality by 6 standard deviations. The prepared states had an average fidelity of $0.9540 \pm 0.0016$ at the source and an average fidelity of $0.9353 ^{+0.0100}_{-0.0209}$ after entanglement distribution, which shows that the quantum states generated by our time-bin entangled photon source can be fully controlled potentially to a level applicable to long-distance advanced quantum network systems.

EPJ Quantum Technology•Sep 4, 2024•9 citations

Resource-efficient parallel entanglement generation for multinode quantum networks via time-bin multiplexing

Wenbo Zhang, Jing Zheng, Yimin Wang +1 more

Nonlocal entanglement generation among multiple remote quantum nodes provides a critical foundation for a variety of counterintuitive quantum applications. The exponential loss of photons transmitting over optical fibers sets an upper limit for entangling these quantum nodes. Here, we propose a resource-efficient and parallel protocol for entangling multiple remote quantum nodes via time-bin multiplexing. The transmission of a single photon with qudit-encoding in the time-bin mode enables entangling multiple stationary qubits in parallel, when single photons and individual stationary qubits interfaces are used and photon-state modulations are properly introduced before subsequently impinging the photon into each interface. Our protocol can generate parallel multipartite entanglement among ($N\geq3$) quantum nodes with the dimension of the photonic time bins independent of $N$, exponentially reducing the requirements for the coherence time of the stationary qubits and for the complexity of the photonic modulations. These distinct features make our protocol particularly advantageous for the development of multinode quantum networks.

quant-pharXiv:2605.03682•May 6, 2026•0 citations
The next generation of telecommunication networks will rely on the distribution of complex quantum resources to enable secure and transformative information processing, utilizing entanglement and superposition. Cluster states-multi-qubit entangled states that retain entanglement under local measurements-are the central resource for measurement-based quantum information processing and compelling for quantum networking applications including blind quantum computing and quantum key agreement. However, transmitting cluster states over optical fiber has remained elusive with previous approaches, as losses scale exponentially with the number of photons. Here, we report the first transmission of a four-qubit cluster state to two parties over a partially deployed single-mode fiber link. The qubits of this state are encoded in two photons with multi-level time-bins. We directly generate the cluster state by exploiting coherent control of a parametric generation process, rendering a resource-intensive controlled-phase gate obsolete. To enable processing of this state, we introduce beam splitting for time-bins via chirped pulse modulation-a novel, reconfigurable Fourier-domain pulse shaping technique. We certify genuine multi-qubit entanglement and demonstrate one-way computing primitives on the transmitted cluster state. Our approach achieves the transmission of cluster states over optical fiber, establishing complex quantum resources fully compatible with telecommunication infrastructure.
The next generation of telecommunication networks will rely on the transmission of complex quantum states to enable secure and transformative information processing, utilizing entanglement and superposition. Cluster states - multipartite entangled states that retain entanglement under local measurements - are a vital resource for quantum networking applications such as blind photonic quantum computing, quantum state teleportation and all-photonic quantum repeaters. However, the transmission of cluster states over optical fiber has remained elusive with previous approaches. Here, we demonstrate the first transmission of a four-qubit cluster state over 25 km of single-mode fiber by using a two-photon multi-level time-bin encoding. We directly generate the state by exploiting coherent control of a parametric generation process, rendering a resource-intensive controlled-phase gate obsolete. To enable efficient and reconfigurable projective measurements on the multi-level time-bin encoded state, we introduce chirped-pulse modulation and implement the first time-bin beam splitter, allowing us to certify genuine multipartite entanglement and to demonstrate one-way computing operations. Our approach enables the transmission of complex quantum states over long-distance fibers, permitting the implementation of multipartite protocols and laying the foundation for large-scale quantum resource networks.
Large and complex optical quantum states are a key resource for fundamental science and applications such as quantum communications, information processing, and metrology. In this context, cluster states are a particularly important class because they enable the realization of universal quantum computers by means of the so-called `one-way' scheme, where processing operations are performed through measurements on the state. While two-level (i.e. qubit) cluster states have been realized thus far, further boosting this computational resource by increasing the number of particles comes at the price of significantly reduced coherence time and detection rates, as well as increased sensitivity to noise. In contrast, the realization of d-level (with d > 2) cluster states offers the possibility to increase quantum resources without changing the number of particles, enables the implementation of efficient computational protocols, as well as coincides with a reduction in the noise sensitivity of the states. Here, we experimentally realize, characterize, and perform one-way processing operations on three-level, four-partite cluster states formed by two photons in the time and frequency domain. We make use of a unique approach based on integrated photonic chips and optical fiber communications components, enabling scalable, deterministic new functionalities.
Quantum networks that can perform user-defined protocols beyond quantum key distribution will require fully controllable entangled quantum states. To expand the available space of generated time-bin entangled states, we demonstrate a time-bin entangled photon source that produces qubit states $|{\psi}\rangle = \alpha |{00}\rangle + \beta |{11}\rangle $ with fully controllable phase and amplitudes. Eight different two-photon states have been selected and prepared from arbitrary states on the reduced two-qubit Bloch sphere. The photon pairs encoded in the time-bin scheme were generated at 2.4 MHz with a visibility of V=0.9475±0.0016V = 0.9475 \pm 0.0016V=0.9475±0.0016 , with a violation of the CHSH Bell’s inequality by 197 standard deviations. After entanglement distribution over 100 km of single-mode fibers, we obtained a visibility of V=0.9541±0.0113V = 0.9541 \pm 0.0113V=0.9541±0.0113 with a violation of the CHSH Bell’s inequality by 6 standard deviations. The prepared states had an average fidelity of 0.9540±0.00160.9540 \pm 0.00160.9540±0.0016 at the source and an average fidelity of 0.9353−0.0209+0.01000.9353 ^{+0.0100}_{-0.0209}0.9353−0.0209+0.0100​ after entanglement distribution, which shows that the quantum states generated by our time-bin entangled photon source can be fully controlled potentially to a level applicable to long-distance advanced quantum network systems.
Nonlocal entanglement generation among multiple remote quantum nodes provides a critical foundation for a variety of counterintuitive quantum applications. The exponential loss of photons transmitting over optical fibers sets an upper limit for entangling these quantum nodes. Here, we propose a resource-efficient and parallel protocol for entangling multiple remote quantum nodes via time-bin multiplexing. The transmission of a single photon with qudit-encoding in the time-bin mode enables entangling multiple stationary qubits in parallel, when single photons and individual stationary qubits interfaces are used and photon-state modulations are properly introduced before subsequently impinging the photon into each interface. Our protocol can generate parallel multipartite entanglement among (N≥3N\geq3N≥3) quantum nodes with the dimension of the photonic time bins independent of NNN, exponentially reducing the requirements for the coherence time of the stationary qubits and for the complexity of the photonic modulations. These distinct features make our protocol particularly advantageous for the development of multinode quantum networks.