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:2409.04250 · Physical Review Research

Photonic multipartite entanglement in discrete variables without arbitrary unitaries

Milica Banić, John E. Sipe, Marco Liscidini

Published Jan 16, 2025• 2 citations
arXivHTMLPDF

Abstract

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.

DOI
10.1103/physrevresearch.7.013060

Related papers

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

Milica Banić, John E. Sipe, Marco Liscidini

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.

arXiv:2305.01797•Physical Review A•Jan 9, 2024•10 citations

Frequency Bin Encoding and Graphs

Milica Banić, John E. Sipe, Marco Liscidini

We present a strategy for designing passive sources of multipartite frequency-bin-encoded states, based on the target state’s graph representation. As examples we present integrated sources of three- and four-photon GHZ states, and four-photon L a 4 states.

•Jan 1, 2024•0 citations

On-chip high-dimensional entangled photon sources

Tavshabad Kaur, Daniel Peace, Jacquiline Romero

Abstract High-dimensional quantum entanglement is an important resource for emerging quantum technologies such as quantum communication and quantum computation. The scalability of metres-long experimental setups limits high-dimensional entanglement in bulk optics. Advancements in quantum technology hinge on reproducible, and reconfigurable quantum devices—including photon sources, which are challenging to achieve in a scalable manner using bulk optics. Advances in nanotechnology and CMOS-compatible integration techniques have enabled the generation of entangled photons on millimeter-scale chips, significantly enhancing scalability, stability, replicability, and miniaturization for real-world quantum applications. In recent years we have seen several chip-scale demonstrations with different discrete degrees of freedom including path, frequency-bin, time-bin, and transverse modes, on many material platforms. A complete quantum photonic integrated circuit requires the generation, manipulation, and detection of quantum states, involving various active and passive quantum photonic components which further increase the degree of complexity. Here, we focus on the high-dimensional versions of qubits—qudits—and review the nonlinear optical processes that facilitate on-chip high-dimensional entangled photon sources, and the currently used material platforms. We discuss a range of current implementations of on-chip high-dimensional entangled photon sources and demonstrated applications. We comment on the current challenges due to the limitations of individual material platforms and present future opportunities in hybrid and heterogeneous integration strategies for the next generation of integrated quantum photonic chips.

arXiv:2409.03224•Journal of Optics•Dec 18, 2024•11 citations

Quantum State Generation with Nonlinear Integrated Photonics: Conventional and Unconventional Approaches

Milica Banić

In this thesis we study the generation of non-classical states of light using nonlinear integrated photonics. We focus first on third-order parametric down-conversion (TOPDC), a process in which pump photons can be down-converted into photon triplets, and which could serve as a source of non-Gaussian states and tripartite discrete-variable entanglement. We investigate the possibility of implementing TOPDC in conventional integrated structures. By comparing the estimated triplet generation rates in a waveguide and a microring resonator, we establish that non-resonant structures appear to be a more promising platform for a near-term demonstration of TOPDC, due to the high generation bandwidth enhancing the rate of triplet generation. We estimate generation rates of ~10 triplets per second for a 1-cm-long waveguide driven by a 100 mW CW pump, a rate that is comparable to or higher than those quoted for other proposals. We then estimate the non-Gaussianity that might be expected in a supermode of the field generated by our sample structures. The predicted non-Gaussianity is negligible in both structures, for different reasons: The generation rate in the ring is too low, while the field generated by the waveguide is highly multimode. We conclude that although a simple SiN waveguide may be a suitable source for a first demonstration of optical TOPDC, the design will need to be improved significantly for observations of non-Gaussianity or tripartite entanglement in the generated light. Indeed, state generation protocols based on conventional spontaneous four-wave mixing sources and postselection appear to be more promising in the near term. We adopt this approach to design integrated sources of postselected multipartite states in a frequency bin encoding scheme. We introduce sources of W states and GHZ states, with kHz generation rates expected for picojoule pump pulses. This platform appears to be promising for the generation of more arbitrary states, including high-dimensional ones consisting of entangled qudits. We review a graph-based strategy that may be useful for designing other devices, and for understanding the limitations of this platform.

•Jun 1, 2024•0 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

Programmable Silicon Photonic Sources of Frequency Bin Entangled Qubits and Qudits

Massimo Borghi, Noemi Tagliavacche, Marco Clementi +12 more

Frequency bin encoding is becoming of widespread use in photonic quantum applications due to its strong noise resilience, the large information content that can be encoded per photon, and the inherent parallelism through which gates can be applied over multiple frequency modes. Ideally, sources of frequency bin qubits and qudits should be programmable, have high brightness, and have tightly spaced spectral modes to be useful for quantum algorithms. Here we present an integrated photonic device that simultaneously met all these requirement. We exploit the coherent generation of photon pairs over multiple ring resonators to overcome the trade-offs that hurdle single resonators. Harnessing the dense integration and phase stability of silicon photonics, we demonstrate a photon pair source of frequency bin qudits and qudits with simultaneously high brightness, fidelity, and purity.

International Conference on Transparent Optical Networks•Jul 2, 2023•0 citations
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 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.
Abstract High-dimensional quantum entanglement is an important resource for emerging quantum technologies such as quantum communication and quantum computation. The scalability of metres-long experimental setups limits high-dimensional entanglement in bulk optics. Advancements in quantum technology hinge on reproducible, and reconfigurable quantum devices—including photon sources, which are challenging to achieve in a scalable manner using bulk optics. Advances in nanotechnology and CMOS-compatible integration techniques have enabled the generation of entangled photons on millimeter-scale chips, significantly enhancing scalability, stability, replicability, and miniaturization for real-world quantum applications. In recent years we have seen several chip-scale demonstrations with different discrete degrees of freedom including path, frequency-bin, time-bin, and transverse modes, on many material platforms. A complete quantum photonic integrated circuit requires the generation, manipulation, and detection of quantum states, involving various active and passive quantum photonic components which further increase the degree of complexity. Here, we focus on the high-dimensional versions of qubits—qudits—and review the nonlinear optical processes that facilitate on-chip high-dimensional entangled photon sources, and the currently used material platforms. We discuss a range of current implementations of on-chip high-dimensional entangled photon sources and demonstrated applications. We comment on the current challenges due to the limitations of individual material platforms and present future opportunities in hybrid and heterogeneous integration strategies for the next generation of integrated quantum photonic chips.
In this thesis we study the generation of non-classical states of light using nonlinear integrated photonics. We focus first on third-order parametric down-conversion (TOPDC), a process in which pump photons can be down-converted into photon triplets, and which could serve as a source of non-Gaussian states and tripartite discrete-variable entanglement. We investigate the possibility of implementing TOPDC in conventional integrated structures. By comparing the estimated triplet generation rates in a waveguide and a microring resonator, we establish that non-resonant structures appear to be a more promising platform for a near-term demonstration of TOPDC, due to the high generation bandwidth enhancing the rate of triplet generation. We estimate generation rates of ~10 triplets per second for a 1-cm-long waveguide driven by a 100 mW CW pump, a rate that is comparable to or higher than those quoted for other proposals. We then estimate the non-Gaussianity that might be expected in a supermode of the field generated by our sample structures. The predicted non-Gaussianity is negligible in both structures, for different reasons: The generation rate in the ring is too low, while the field generated by the waveguide is highly multimode. We conclude that although a simple SiN waveguide may be a suitable source for a first demonstration of optical TOPDC, the design will need to be improved significantly for observations of non-Gaussianity or tripartite entanglement in the generated light. Indeed, state generation protocols based on conventional spontaneous four-wave mixing sources and postselection appear to be more promising in the near term. We adopt this approach to design integrated sources of postselected multipartite states in a frequency bin encoding scheme. We introduce sources of W states and GHZ states, with kHz generation rates expected for picojoule pump pulses. This platform appears to be promising for the generation of more arbitrary states, including high-dimensional ones consisting of entangled qudits. We review a graph-based strategy that may be useful for designing other devices, and for understanding the limitations of this platform.
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.
Frequency bin encoding is becoming of widespread use in photonic quantum applications due to its strong noise resilience, the large information content that can be encoded per photon, and the inherent parallelism through which gates can be applied over multiple frequency modes. Ideally, sources of frequency bin qubits and qudits should be programmable, have high brightness, and have tightly spaced spectral modes to be useful for quantum algorithms. Here we present an integrated photonic device that simultaneously met all these requirement. We exploit the coherent generation of photon pairs over multiple ring resonators to overcome the trade-offs that hurdle single resonators. Harnessing the dense integration and phase stability of silicon photonics, we demonstrate a photon pair source of frequency bin qudits and qudits with simultaneously high brightness, fidelity, and purity.