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

Wave-particle duality in orbital angular momentum based quantum delayed-choice experiment using diffractive neural networks

Dawei Lyu, Qianke Wang, Jun Liu, Jian Wang

Published Oct 3, 2025• 0 citations
Publisher

Abstract

Abstract Wave-particle duality is a foundational yet counterintuitive feature of quantum mechanics, typically demonstrated via delayed-choice and quantum delayed-choice (QDC) experi ments. Photon-based implementations commonly rely on polarization or path degrees of freedom (DoFs), but these approaches present limitations: polarization is restricted to two dimensions, and the path-based schemes, while scalable, face increasing challenges in opti cal complexity and interferometric stability as the dimensionality grows. Here, we present a scalable QDC scheme leveraging the orbital angular momentum (OAM) of photons that overcomes these limitations. Instead of directly encoding paths in OAM states, we encode qubits in subsystems of the OAM DoF—specifically, its signs and amplitudes—and real ize a controlled-Hadamard (CH) gate with 98.73±0.02% fidelity on these qubits using a diffractive neural network. This allows us to demonstrate the QDC experiment within the OAM subsystems, achieving interference transitions between wave-like and particle like behaviors, with fidelities exceeding 99%. Our results show that wave-particle duality extends beyond intrinsic DoFs to qubits encoded in internal substructures of those DoFs, offering a broader perspective on the fundamental nature of quantum behavior.

DOI
10.21203/rs.3.rs-7658122/v1

Related papers

Wave-particle duality in orbital angular momentum-based quantum delayed-choice experiment

Da-Wei Lyu, Qian-ke Wang, Jun Liu +1 more

Wave-particle duality is a foundational feature of quantum mechanics and can be demonstrated via delayed-choice and quantum delayed-choice (QDC) experiments. Photon-based implementations commonly rely on polarization or path degrees of freedom (DoFs), but these approaches present limitations: polarization is restricted to two dimensions, and the path-based schemes, although scalable, face increasing challenges in optical complexity and interferometric stability as the dimensionality grows. Here, we present a scalable QDC scheme leveraging the orbital angular momentum (OAM) of photons that overcomes these limitations. Instead of directly encoding paths in OAM states, we encode qubits in subsystems of the OAM DoF—specifically its signs and amplitudes—and realize a controlled-Hadamard gate with 98.73(2)% fidelity on these qubits using a diffractive neural network. This allows us to demonstrate the QDC experiment within the OAM subsystems and observe interference transitions between wave-like and particle-like behaviors in the space structured by these subsystems, with fidelities exceeding 99%. Our results show that wave-particle duality extends beyond intrinsic DoFs to qubits encoded in internal substructures of those DoFs, offering a broader perspective on the fundamental nature of quantum behavior.

Advanced Photonics•Jun 18, 2026•0 citations

A generalized multipath delayed-choice experiment on a large-scale quantum nanophotonic chip

Xiaojiong Chen, Yaohao Deng, Shuheng Liu +15 more

Abstract Bohr’s complementarity is one central tenet of quantum physics. The paradoxical wave-particle duality of quantum matters and photons has been tested in Young’s double-slit (double-path) interferometers. The object exclusively exhibits wave and particle nature, depending measurement apparatus that can be delayed chosen to rule out too-naive interpretations of quantum complementarity. All experiments to date have been implemented in the double-path framework, while it is of fundamental interest to study complementarity in multipath interferometric systems. Here, we demonstrate generalized multipath wave-particle duality in a quantum delayed-choice experiment, implemented by large-scale silicon-integrated multipath interferometers. Single-photon displays sophisticated transitions between wave and particle characters, determined by the choice of quantum-controlled generalized Hadamard operations. We characterise particle-nature by multimode which-path information and wave-nature by multipath coherence of interference, and demonstrate the generalisation of Bohr’s multipath duality relation. Our work provides deep insights into multidimensional quantum physics and benchmarks controllability of integrated photonic quantum technology.

•Jan 1, 2021•30 citations

A generalised multipath delayed-choice experiment on a large-scale quantum nanophotonic chip

Xiaojiong Chen, Yaohao Deng, Shuheng Liu +15 more

Bohr’s complementarity is one central tenet of quantum physics. The paradoxical wave-particle duality of quantum matters and photons has been tested in Young’s double-slit (double-path) interferometers. The object exclusively exhibits wave and particle nature, depending measurement apparatus that can be delayed chosen to rule out too-naive interpretations of quantum complementarity. All experiments to date have been implemented in the double-path framework, while it is of fundamental interests to study complementarity in multipath interferometric systems. Here we demonstrate generalised multipath wave-particle duality in a quantum delayed-choice experiment, implemented by large-scale silicon-integrated multipath interferometers. Single-photon displays sophisticated transitions between wave and particle characters, determined by the choice of quantum-controlled generalised Hadamard operations. We characterise particle-nature by multimode which-path information and wave-nature by multipath coherence of interference, and demonstrate the generalisation of Bohr’s multipath duality relation. Our work provides deep insights into multidimensional quantum physics and benchmarks controllability of integrated photonic quantum technology.

SPIE Conference on Quantum and Nonlinear Optics•Oct 8, 2021•0 citations

Fourier Transform of the Orbital Angular Momentum of a Single Photon

Jaroslav Kysela, Xiaoqin Gao, Borivoje Dakić

Optical networks implementing single-qudit quantum gates may exhibit superior properties to those for qubits as each optical element in the network can work in parallel on many optical modes simultaneously. We present a class of such networks that implements in a deterministic and efficient way the quantum Fourier transform (QFT) in an arbitrarily high dimension. These networks redistribute the initial quantum state into the orbital angular momentum (OAM) and path degrees of freedom and offer two modes of operation. Either the OAM-only QFT can be implemented, which uses the path as an internal auxiliary degree of freedom, or the path-only QFT is implemented, which uses the OAM as the auxiliary degree of freedom. The resources for both schemes scale linearly $O(d)$ with the dimension $d$ of the system, beating the best known bounds for the path-encoded QFT. While the QFT of the orbital-angular-momentum states of single photons has been applied in a multitude of experiments, these schemes require specially designed elements with nontrivial phase profiles. In contrast, we propose a different approach that utilizes only conventional optical elements.

arXiv:2004.12788•Physical Review Applied•Sep 14, 2020•15 citations

Polarization and Orbital Angular Momentum Encoded Quantum Toffoli Gate Enabled by Diffractive Neural Networks

Qianke Wang, Dawei Lyu, Jun Liu +1 more

Controlled quantum gates play a crucial role in enabling quantum universal operations by facilitating interactions between qubits. Direct implementation of three-qubit gates simplifies the design of quantum circuits, thereby being conducive to performing complex quantum algorithms. Here, we propose and present an experimental demonstration of a quantum Toffoli gate fully exploiting the polarization and orbital angular momentum of a single photon. The Toffoli gate is implemented using the polarized diffractive neural networks scheme, achieving a mean truth table visibility of 97.27±0.20%. We characterize the gate's performance through quantum state tomography on 216 different input states and quantum process tomography, which yields a process fidelity of 94.05±0.02%. Our method offers a novel approach for realizing the Toffoli gate without requiring exponential optical elements while maintaining extensibility to the implementation of other three-qubit gates.

arXiv:2411.17266•Physical Review Letters•Sep 30, 2024•12 citations

A generalized multipath delayed-choice experiment on a large-scale quantum nanophotonic chip

Xiaojiong Chen, Yaohao Deng, Shuheng Liu +15 more

Bohr's complementarity is one central tenet of quantum physics. The paradoxical wave-particle duality of quantum matters and photons has been tested in Young's double-slit (double-path) interferometers. The object exclusively exhibits wave and particle nature, depending measurement apparatus that can be delayed chosen to rule out too-naive interpretations of quantum complementarity. All experiments to date have been implemented in the double-path framework, while it is of fundamental interest to study complementarity in multipath interferometric systems. Here, we demonstrate generalized multipath wave-particle duality in a quantum delayed-choice experiment, implemented by large-scale silicon-integrated multipath interferometers. Single-photon displays sophisticated transitions between wave and particle characters, determined by the choice of quantum-controlled generalized Hadamard operations. We characterise particle-nature by multimode which-path information and wave-nature by multipath coherence of interference, and demonstrate the generalisation of Bohr's multipath duality relation. Our work provides deep insights into multidimensional quantum physics and benchmarks controllability of integrated photonic quantum technology.

arXiv:2105.05580•Nature Communications•May 7, 2021•31 citations
Abstract Wave-particle duality is a foundational yet counterintuitive feature of quantum mechanics, typically demonstrated via delayed-choice and quantum delayed-choice (QDC) experi ments. Photon-based implementations commonly rely on polarization or path degrees of freedom (DoFs), but these approaches present limitations: polarization is restricted to two dimensions, and the path-based schemes, while scalable, face increasing challenges in opti cal complexity and interferometric stability as the dimensionality grows. Here, we present a scalable QDC scheme leveraging the orbital angular momentum (OAM) of photons that overcomes these limitations. Instead of directly encoding paths in OAM states, we encode qubits in subsystems of the OAM DoF—specifically, its signs and amplitudes—and real ize a controlled-Hadamard (CH) gate with 98.73±0.02% fidelity on these qubits using a diffractive neural network. This allows us to demonstrate the QDC experiment within the OAM subsystems, achieving interference transitions between wave-like and particle like behaviors, with fidelities exceeding 99%. Our results show that wave-particle duality extends beyond intrinsic DoFs to qubits encoded in internal substructures of those DoFs, offering a broader perspective on the fundamental nature of quantum behavior.
Wave-particle duality is a foundational feature of quantum mechanics and can be demonstrated via delayed-choice and quantum delayed-choice (QDC) experiments. Photon-based implementations commonly rely on polarization or path degrees of freedom (DoFs), but these approaches present limitations: polarization is restricted to two dimensions, and the path-based schemes, although scalable, face increasing challenges in optical complexity and interferometric stability as the dimensionality grows. Here, we present a scalable QDC scheme leveraging the orbital angular momentum (OAM) of photons that overcomes these limitations. Instead of directly encoding paths in OAM states, we encode qubits in subsystems of the OAM DoF—specifically its signs and amplitudes—and realize a controlled-Hadamard gate with 98.73(2)% fidelity on these qubits using a diffractive neural network. This allows us to demonstrate the QDC experiment within the OAM subsystems and observe interference transitions between wave-like and particle-like behaviors in the space structured by these subsystems, with fidelities exceeding 99%. Our results show that wave-particle duality extends beyond intrinsic DoFs to qubits encoded in internal substructures of those DoFs, offering a broader perspective on the fundamental nature of quantum behavior.
Abstract Bohr’s complementarity is one central tenet of quantum physics. The paradoxical wave-particle duality of quantum matters and photons has been tested in Young’s double-slit (double-path) interferometers. The object exclusively exhibits wave and particle nature, depending measurement apparatus that can be delayed chosen to rule out too-naive interpretations of quantum complementarity. All experiments to date have been implemented in the double-path framework, while it is of fundamental interest to study complementarity in multipath interferometric systems. Here, we demonstrate generalized multipath wave-particle duality in a quantum delayed-choice experiment, implemented by large-scale silicon-integrated multipath interferometers. Single-photon displays sophisticated transitions between wave and particle characters, determined by the choice of quantum-controlled generalized Hadamard operations. We characterise particle-nature by multimode which-path information and wave-nature by multipath coherence of interference, and demonstrate the generalisation of Bohr’s multipath duality relation. Our work provides deep insights into multidimensional quantum physics and benchmarks controllability of integrated photonic quantum technology.
Bohr’s complementarity is one central tenet of quantum physics. The paradoxical wave-particle duality of quantum matters and photons has been tested in Young’s double-slit (double-path) interferometers. The object exclusively exhibits wave and particle nature, depending measurement apparatus that can be delayed chosen to rule out too-naive interpretations of quantum complementarity. All experiments to date have been implemented in the double-path framework, while it is of fundamental interests to study complementarity in multipath interferometric systems. Here we demonstrate generalised multipath wave-particle duality in a quantum delayed-choice experiment, implemented by large-scale silicon-integrated multipath interferometers. Single-photon displays sophisticated transitions between wave and particle characters, determined by the choice of quantum-controlled generalised Hadamard operations. We characterise particle-nature by multimode which-path information and wave-nature by multipath coherence of interference, and demonstrate the generalisation of Bohr’s multipath duality relation. Our work provides deep insights into multidimensional quantum physics and benchmarks controllability of integrated photonic quantum technology.
Optical networks implementing single-qudit quantum gates may exhibit superior properties to those for qubits as each optical element in the network can work in parallel on many optical modes simultaneously. We present a class of such networks that implements in a deterministic and efficient way the quantum Fourier transform (QFT) in an arbitrarily high dimension. These networks redistribute the initial quantum state into the orbital angular momentum (OAM) and path degrees of freedom and offer two modes of operation. Either the OAM-only QFT can be implemented, which uses the path as an internal auxiliary degree of freedom, or the path-only QFT is implemented, which uses the OAM as the auxiliary degree of freedom. The resources for both schemes scale linearly O(d)O(d)O(d) with the dimension ddd of the system, beating the best known bounds for the path-encoded QFT. While the QFT of the orbital-angular-momentum states of single photons has been applied in a multitude of experiments, these schemes require specially designed elements with nontrivial phase profiles. In contrast, we propose a different approach that utilizes only conventional optical elements.
Controlled quantum gates play a crucial role in enabling quantum universal operations by facilitating interactions between qubits. Direct implementation of three-qubit gates simplifies the design of quantum circuits, thereby being conducive to performing complex quantum algorithms. Here, we propose and present an experimental demonstration of a quantum Toffoli gate fully exploiting the polarization and orbital angular momentum of a single photon. The Toffoli gate is implemented using the polarized diffractive neural networks scheme, achieving a mean truth table visibility of 97.27±0.20%. We characterize the gate's performance through quantum state tomography on 216 different input states and quantum process tomography, which yields a process fidelity of 94.05±0.02%. Our method offers a novel approach for realizing the Toffoli gate without requiring exponential optical elements while maintaining extensibility to the implementation of other three-qubit gates.
Bohr's complementarity is one central tenet of quantum physics. The paradoxical wave-particle duality of quantum matters and photons has been tested in Young's double-slit (double-path) interferometers. The object exclusively exhibits wave and particle nature, depending measurement apparatus that can be delayed chosen to rule out too-naive interpretations of quantum complementarity. All experiments to date have been implemented in the double-path framework, while it is of fundamental interest to study complementarity in multipath interferometric systems. Here, we demonstrate generalized multipath wave-particle duality in a quantum delayed-choice experiment, implemented by large-scale silicon-integrated multipath interferometers. Single-photon displays sophisticated transitions between wave and particle characters, determined by the choice of quantum-controlled generalized Hadamard operations. We characterise particle-nature by multimode which-path information and wave-nature by multipath coherence of interference, and demonstrate the generalisation of Bohr's multipath duality relation. Our work provides deep insights into multidimensional quantum physics and benchmarks controllability of integrated photonic quantum technology.