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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
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Revealing genuine optical-path entanglement
F Monteiro1, V Caprara Vivoli1, T Guerreiro1
1Group of Applied Physics, University of Geneva, CH-1211 Geneva 4, Switzerland.
Physical Review Letters
|May 16, 2015
Summary
Researchers developed a scalable protocol using local measurements to detect multipartite entanglement in optical paths. This method avoids postselection and assumptions about photon number, proving useful for quantum networks.
Area of Science:
- Quantum Optics
- Quantum Information Science
- Experimental Quantum Physics
Background:
- Detecting entanglement in multi-path systems is crucial for quantum information processing.
- Existing methods often require complex setups or strict experimental conditions.
- Scalable and robust entanglement detection protocols are needed for advancing quantum technologies.
Purpose of the Study:
- To propose and experimentally validate a scalable protocol for detecting multipartite entanglement.
- To enable entanglement detection in multiple optical paths sharing a single photon.
- To develop a method robust against photon loss and avoiding postselection.
Main Methods:
- Utilized local measurements combining single-photon detection with small displacement operations.
- Developed an entanglement witness applicable to a subspace with at most one photon per path.
- Performed experimental demonstrations with two and three optical paths.
Main Results:
- Successfully demonstrated a scalable protocol for detecting genuinely multipartite entanglement.
- The proposed entanglement witness requires no postselection or assumptions on photon number.
- Experimental results confirmed the protocol's scalability and resistance to photon loss.
Conclusions:
- The developed protocol offers a practical and robust method for detecting multipartite entanglement in optical systems.
- This technique guarantees entanglement within a specific subspace, simplifying analysis.
- Potential applications include quantum network certification and advancing distributed quantum computing.
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