Metropolitan-scale ion-photon entanglement via a quantum network node with hybrid multiplexing enhancements

Area of Science:

• Quantum Information Science
• Atomic, Molecular, and Optical Physics

Background:

• Quantum networks and quantum repeaters are essential for scaling quantum information systems.
• High rates of heralded remote entanglement distribution are necessary to overcome decoherence in quantum nodes.

Purpose of the Study:

• To experimentally realize a multiplexed quantum network node to enhance entanglement distribution rates.
• To investigate the potential of multiplexing for accelerating heralded entanglement generation in a quantum network.

Main Methods:

• Utilized a chain of 40Ca+ ions as the basis for the quantum network node.
• Implemented a hybrid multiplexing scheme generating up to 44 time-bin modes.
• Employed a dual-type framework to protect quantum information during entangling attempts.

Main Results:

• Achieved a heralded ion-photon entanglement success rate of 4.28 s^-1 over a 12 km fiber.
• Demonstrated a memory coherence time of 366 ms, exceeding the entanglement generation time.
• Successfully boosted the entangling rate through multiplexing enhancement.

Conclusions:

• The developed multiplexed quantum network node significantly enhances heralded entanglement distribution rates.
• The experimental results demonstrate the viability of multiplexing for practical quantum network applications.
• The achieved coherence time indicates robust quantum information storage within the ion-based node.