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

Nanophotonics

Robust Generation of Topological Biphoton Mode via Adiabatic Passage

Jaesung Lim, Jihwan Kim, Dong-Gil Im, Kyungdeuk Park, Dongkyu Kim, Yonggi Jo, Yong Sup Ihn

Published Jul 29, 2026• 0 citations
Publisher

Abstract

Topological waveguide arrays support robust mode propagation in the presence of fabrication imperfections, providing a significant advantage for on-chip quantum information processing. However, this robustness does not fully extend to nonlinear biphoton generation. Structural disorder can enhance the excitation of nontopological biphoton modes during nonlinear interactions, which degrades the quantum properties of the generated state. To overcome this limitation, we propose an adiabatic passage that connects an isolated site to a topological defect array. By initiating the nonlinear process in a strongly isolated regime, nonlinear coupling to unwanted modes is effectively suppressed, thereby preserving the Schmidt number of the generated state. The subsequent adiabatic connection facilitates the high fidelity transfer of the generated biphoton into the topological biphoton mode. Our numerical simulations demonstrate that, unlike conventional topological structures, the adiabatic scheme maintains both high biphoton fidelity and a unit Schmidt number in the presence of waveguide gap disorder. Furthermore, we show that this robustness extends to path entangled NOON states, achieving a near-unity quantum interference visibility. Our approach provides a practical design strategy for disorder-tolerant integrated quantum photonic devices.

DOI
10.1002/nap2.70223

Related papers

Robust Generation of Topological Biphoton Mode via Adiabatic Passage

Jaesung Lim, Jihwan Kim, Dong-Gil Im +4 more

Topological waveguide arrays support robust mode propagation in the presence of fabrication imperfections, providing a significant advantage for on-chip quantum information processing. However, this robustness does not fully extend to nonlinear biphoton generation. Structural disorder can enhance the excitation of non-topological biphoton modes during nonlinear interactions, which degrades the quantum properties of the generated state. To overcome this limitation, we propose an adiabatic passage that connects an isolated site to a topological defect array. By initiating the nonlinear process in a strongly isolated regime, nonlinear coupling to unwanted modes is effectively suppressed, thereby preserving the Schmidt number of the generated state. The subsequent adiabatic connection facilitates the high fidelity transfer of the generated biphoton into the topological biphoton mode. Our numerical simulations demonstrate that, unlike conventional topological structures, the adiabatic scheme maintains both high biphoton fidelity and a unit Schmidt number in the presence of waveguide gap disorder. Furthermore, we show that this robustness extends to path entangled NOON states, achieving a near-unity quantum interference visibility. Our approach provides a practical design strategy for disorder-tolerant integrated quantum photonic devices.

quant-pharXiv:2606.19786•Jun 19, 2026•0 citations

Topological On-Chip Quantum Photonics for Nonlinear Biphoton Entanglement

Hesam Zaravashan, Maryam Khodadadi, Ali Ali +2 more

Integrated quantum photonics promises scalable quantum technologies but remains limited by fabrication-induced disorder, phase instability, and loss, which degrade interference and entanglement. In this paper, a fully topological approach to both linear routing and nonlinear biphoton generation is demonstrated on the same chip. A valley-Hall lattice is engineered to create a dispersion-stable edge mode that supports spontaneous four-wave mixing with efficient phase matching. The generated signal-idler photon pairs are routed by a topological power splitter that maintains a 50:50 ratio and preserves relative phase, even through a sharp 60° bend. Strong suppression of backscattering and minimal dispersion enable high-visibility twophoton interference without active recalibration. This unified platform simultaneously provides robust guiding, coherent splitting, and high-fidelity entanglement generation, overcoming key limitations of conventional integrated photonics. These results establish topological photonic structures as a practical route toward fabrication-tolerant, phase-stable, and scalable quantum light sources and circuits for next-generation quantum communication, computation, and sensing.

European Conference on Antennas and Propagation•Apr 1, 2026•0 citations

Self-induced manipulation of biphoton entanglement in topologically distinct modes

Wei-Wei Zhang, Chao Chen, Jizhou Wu

Biphoton states have shown promising applications in quantum information processing, including quantum communications, quantum metrology, and quantum imaging. The generation and manipulation of biphoton entanglement in topologically distinct modes paves the way in this direction. Here we present a comprehensive method for regulating the topological properties of the system by combining the nonlinearity in waveguides, i.e., nonlinearity in the waveguide coupling materials, and the waveguide lattice structure. Our method enables the generation of topological biphoton states with injected pump activation on the topologically trivial modes. This is realized through self-induced manipulation on pump-dependent nonlinear couplings on the defects, which is unable to be realized while there are no such nonlinear couplings. Specifically, by including the nonlinear gain/loss mechanism in the coupling between the nearest-neighbor waveguides and the third-order Kerr nonlinearity effect along the waveguides, the injected pump power will be the controllable parameter for the manipulation of the topology in the defect states and the generation of biphoton entanglement states. We also present an experimental proposal to realize our scheme and its generalization in the contemporaneous "active" topological photonics time-bin platforms. Our method can be used in other Su-Schrieffer-Heeger (SSH) models with various defect configurations. Our method enables the reusability and versatility of SSH lattice chips and their application for fault-tolerant quantum information processing, promoting the industrialization process of quantum technology.

quant-pharXiv:2511.05835•Physical Review Applied•Nov 11, 2025•1 citation

Spectrally robust photon-pair generation in topological waveguide arrays

A. Zecchetto, J-R. Coudevylle, M. Morassi +4 more

Harnessing topological effects offers a route to protect quantum states of light from imperfections, potentially enabling more robust platforms for quantum information processing. This capability is particularly relevant for active photonic circuits that generate quantum light directly on-chip. However, the impact of topology on the spectral properties of parametric processes, crucial for scalable quantum photonic circuits, remains largely unexplored. Here, we address this question by investigating photon-pair generation via spontaneous parametric down-conversion (SPDC) in nonlinear waveguide arrays, combining experiment and theory. A systematic comparison of uniform, trivial, and topological Su-Schrieffer-Heeger (SSH) arrays reveals that only the topological configuration preserves a stable SPDC resonance spectrum under coupling disorder, with fluctuations in the resonance wavelength reduced by more than an order of magnitude. An analytical model captures the origin of this robustness in the band-structure properties of the interacting modes. Numerical analysis further shows that each SSH array can operate as a robust photon-pair source, enabling stable interference between multiple such sources and the generation of high-dimensional entangled states with high fidelity. These results establish nonlinear waveguide arrays as a promising platform for harnessing the interplay of topology and nonlinearity in quantum photonic circuits.

PRX Quantum•Sep 17, 2026•0 citations

High-dimensional entanglement and topological protection in nonlinear waveguide arrays

Alessandro Zecchetto, Arnault Raymond, Jean‐René Coudevylle +6 more

We demonstrate a nonlinear AlGaAs photonic chip generating biphotons with high-dimensional spatial correlations. Photon pairs are generated by parametric down conversion in a waveguide array and simultaneously spread through quantum walks along the various waveguides, allowing to generate various types of high-dimensional entangled states of light. We further implement the Su-Schriefer-Heeger model and demonstrate the topological protection of the SPDC process against disorder. These results highlight nonlinear waveguide arrays as a promising platform for exploring the interplay between nonlinearity, disorder and topology in quantum photonic circuits.

•Sep 22, 2025•0 citations

Manipulating multiple optical parametric processes in photonic topological insulators

Zhen Jiang, Bo Ji, Yanghe Chen +2 more

Topological quantum optics has endowed integrated quantum devices with novel functionalities, including unidirectional transport and immunity to structural defects. Here we propose topological interfaces that support two distinct edge modes with different frequency ranges. The nonlinear four-wave mixing processes in the topological interfaces lead to the generation of signal and idler photons, each corresponding to distinct edge modes. By designing a diamondlike topological structure, we can couple the signal and idler photons into opposite branches, leading to spatial separation of the photon pairs. This behavior enables on-chip generation and flexible control of the topological biphoton states. More importantly, the biphoton states are inborn topologically protected, showing robustness against sharp bends and disorders. Our proposal offers the possibility of robust, multifunctional topological quantum devices, which may find applications in quantum information processing.

arXiv:2401.06418•Physical review. B./Physical review. B•May 13, 2024•4 citations
Topological waveguide arrays support robust mode propagation in the presence of fabrication imperfections, providing a significant advantage for on-chip quantum information processing. However, this robustness does not fully extend to nonlinear biphoton generation. Structural disorder can enhance the excitation of nontopological biphoton modes during nonlinear interactions, which degrades the quantum properties of the generated state. To overcome this limitation, we propose an adiabatic passage that connects an isolated site to a topological defect array. By initiating the nonlinear process in a strongly isolated regime, nonlinear coupling to unwanted modes is effectively suppressed, thereby preserving the Schmidt number of the generated state. The subsequent adiabatic connection facilitates the high fidelity transfer of the generated biphoton into the topological biphoton mode. Our numerical simulations demonstrate that, unlike conventional topological structures, the adiabatic scheme maintains both high biphoton fidelity and a unit Schmidt number in the presence of waveguide gap disorder. Furthermore, we show that this robustness extends to path entangled NOON states, achieving a near-unity quantum interference visibility. Our approach provides a practical design strategy for disorder-tolerant integrated quantum photonic devices.
Topological waveguide arrays support robust mode propagation in the presence of fabrication imperfections, providing a significant advantage for on-chip quantum information processing. However, this robustness does not fully extend to nonlinear biphoton generation. Structural disorder can enhance the excitation of non-topological biphoton modes during nonlinear interactions, which degrades the quantum properties of the generated state. To overcome this limitation, we propose an adiabatic passage that connects an isolated site to a topological defect array. By initiating the nonlinear process in a strongly isolated regime, nonlinear coupling to unwanted modes is effectively suppressed, thereby preserving the Schmidt number of the generated state. The subsequent adiabatic connection facilitates the high fidelity transfer of the generated biphoton into the topological biphoton mode. Our numerical simulations demonstrate that, unlike conventional topological structures, the adiabatic scheme maintains both high biphoton fidelity and a unit Schmidt number in the presence of waveguide gap disorder. Furthermore, we show that this robustness extends to path entangled NOON states, achieving a near-unity quantum interference visibility. Our approach provides a practical design strategy for disorder-tolerant integrated quantum photonic devices.
Integrated quantum photonics promises scalable quantum technologies but remains limited by fabrication-induced disorder, phase instability, and loss, which degrade interference and entanglement. In this paper, a fully topological approach to both linear routing and nonlinear biphoton generation is demonstrated on the same chip. A valley-Hall lattice is engineered to create a dispersion-stable edge mode that supports spontaneous four-wave mixing with efficient phase matching. The generated signal-idler photon pairs are routed by a topological power splitter that maintains a 50:50 ratio and preserves relative phase, even through a sharp 60° bend. Strong suppression of backscattering and minimal dispersion enable high-visibility twophoton interference without active recalibration. This unified platform simultaneously provides robust guiding, coherent splitting, and high-fidelity entanglement generation, overcoming key limitations of conventional integrated photonics. These results establish topological photonic structures as a practical route toward fabrication-tolerant, phase-stable, and scalable quantum light sources and circuits for next-generation quantum communication, computation, and sensing.
Biphoton states have shown promising applications in quantum information processing, including quantum communications, quantum metrology, and quantum imaging. The generation and manipulation of biphoton entanglement in topologically distinct modes paves the way in this direction. Here we present a comprehensive method for regulating the topological properties of the system by combining the nonlinearity in waveguides, i.e., nonlinearity in the waveguide coupling materials, and the waveguide lattice structure. Our method enables the generation of topological biphoton states with injected pump activation on the topologically trivial modes. This is realized through self-induced manipulation on pump-dependent nonlinear couplings on the defects, which is unable to be realized while there are no such nonlinear couplings. Specifically, by including the nonlinear gain/loss mechanism in the coupling between the nearest-neighbor waveguides and the third-order Kerr nonlinearity effect along the waveguides, the injected pump power will be the controllable parameter for the manipulation of the topology in the defect states and the generation of biphoton entanglement states. We also present an experimental proposal to realize our scheme and its generalization in the contemporaneous "active" topological photonics time-bin platforms. Our method can be used in other Su-Schrieffer-Heeger (SSH) models with various defect configurations. Our method enables the reusability and versatility of SSH lattice chips and their application for fault-tolerant quantum information processing, promoting the industrialization process of quantum technology.
Harnessing topological effects offers a route to protect quantum states of light from imperfections, potentially enabling more robust platforms for quantum information processing. This capability is particularly relevant for active photonic circuits that generate quantum light directly on-chip. However, the impact of topology on the spectral properties of parametric processes, crucial for scalable quantum photonic circuits, remains largely unexplored. Here, we address this question by investigating photon-pair generation via spontaneous parametric down-conversion (SPDC) in nonlinear waveguide arrays, combining experiment and theory. A systematic comparison of uniform, trivial, and topological Su-Schrieffer-Heeger (SSH) arrays reveals that only the topological configuration preserves a stable SPDC resonance spectrum under coupling disorder, with fluctuations in the resonance wavelength reduced by more than an order of magnitude. An analytical model captures the origin of this robustness in the band-structure properties of the interacting modes. Numerical analysis further shows that each SSH array can operate as a robust photon-pair source, enabling stable interference between multiple such sources and the generation of high-dimensional entangled states with high fidelity. These results establish nonlinear waveguide arrays as a promising platform for harnessing the interplay of topology and nonlinearity in quantum photonic circuits.
We demonstrate a nonlinear AlGaAs photonic chip generating biphotons with high-dimensional spatial correlations. Photon pairs are generated by parametric down conversion in a waveguide array and simultaneously spread through quantum walks along the various waveguides, allowing to generate various types of high-dimensional entangled states of light. We further implement the Su-Schriefer-Heeger model and demonstrate the topological protection of the SPDC process against disorder. These results highlight nonlinear waveguide arrays as a promising platform for exploring the interplay between nonlinearity, disorder and topology in quantum photonic circuits.
Topological quantum optics has endowed integrated quantum devices with novel functionalities, including unidirectional transport and immunity to structural defects. Here we propose topological interfaces that support two distinct edge modes with different frequency ranges. The nonlinear four-wave mixing processes in the topological interfaces lead to the generation of signal and idler photons, each corresponding to distinct edge modes. By designing a diamondlike topological structure, we can couple the signal and idler photons into opposite branches, leading to spatial separation of the photon pairs. This behavior enables on-chip generation and flexible control of the topological biphoton states. More importantly, the biphoton states are inborn topologically protected, showing robustness against sharp bends and disorders. Our proposal offers the possibility of robust, multifunctional topological quantum devices, which may find applications in quantum information processing.