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Updated: Jan 18, 2026
07:56
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
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Entangled measurement for W states
Geobae Park1, Holger F Hofmann2, Ryo Okamoto1,3
1Department of Electronic Science and Engineering, Kyoto University, Kyotodaigakukatsura, Nishikyo-ku, Kyoto 615-8510, Japan.
Science Advances
|September 12, 2025
Summary
Researchers developed a new method for entangled measurements in three-qubit systems. This technique uses discrete Fourier transformation (DFT) to project states, enabling new quantum network protocols.
Area of Science:
- Quantum Information Science
- Quantum Optics
- Quantum Computing
Background:
- Entangled measurements are crucial for quantum information processing tasks like quantum teleportation.
- Current methods primarily focus on bipartite systems or Greenberger-Horne-Zeilinger (GHZ) states.
- Realizing entangled measurements for multipartite systems remains a significant challenge.
Purpose of the Study:
- To demonstrate a practical scheme for performing entangled measurements on three-qubit states.
- To overcome the limitations of existing methods that focus on bipartite or GHZ states.
- To enable new quantum network protocols for multipartite systems.
Main Methods:
- Utilizing the cyclic shift symmetry inherent in the discrete Fourier transformation (DFT) of bosonic modes.
- Employing DFT measurement outcomes to deterministically project multiqubit states onto specific entangled states.
- Constructing a three-mode DFT optical circuit for experimental realization.
Main Results:
- Successfully demonstrated three-qubit state discrimination using the proposed scheme.
- Achieved a measurement discrimination fidelity of 0.871 ± 0.039.
- Validated the projection of multiqubit states onto three-qubit states via DFT symmetry detection.
Conclusions:
- The developed scheme provides a practical method for entangled measurements in three-qubit systems.
- This experimental demonstration paves the way for advanced quantum network protocols involving multipartite systems.
- The use of DFT cyclic shift symmetry offers a novel approach to quantum state manipulation and measurement.
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