Deterministic distribution of multipartite entanglement in a quantum network by continuous-variable polarization...

Area of Science:

• Quantum Information Science
• Quantum Communication Networks
• Quantum Optics

Background:

• Deterministic entanglement distribution is crucial for practical quantum information applications.
• Current methods face challenges in distributing entanglement over long distances in existing fiber networks.

Purpose of the Study:

• To propose a feasible scheme for deterministic quadripartite entanglement distribution.
• To enable entanglement distribution for multiple remote users via optical fiber.
• To facilitate the development of metropolitan quantum networks.

Main Methods:

• Utilizing continuous-variable (CV) polarization states for entanglement.
• A quantum server prepares and distributes quadripartite CV polarization entanglement.
• Employing a beam splitter network to generate different entanglement types (GHZ-like, cluster-like).

Main Results:

• Successfully demonstrated deterministic distribution of quadripartite entanglement.
• Achieved local oscillation-free measurement of CV polarization entanglement.
• Confirmed the generation of both GHZ-like and cluster-like states using extended criteria.

Conclusions:

• The proposed scheme enables long-distance entanglement distribution in commercial optical fiber networks.
• The protocol is directly extendable to quantum networks with more users.
• This work is essential for building metropolitan quantum networks.