Telecom-Wavelength Quantum Repeater Node Based on a Trapped-Ion Processor

Area of Science:

• Quantum Information Science
• Quantum Communication Technology
• Atomic Physics

Background:

• Quantum repeaters are essential for long-distance quantum communication.
• Trapped ions offer promising functionalities for quantum repeater nodes.

Purpose of the Study:

• To present a quantum repeater node based on trapped ions.
• To demonstrate entanglement distribution and swapping over optical fibers.
• To project the scalability of the system for future quantum networks.

Main Methods:

• Utilizing trapped ions as single-photon emitters, quantum memories, and quantum processors.
• Establishing entanglement across two independent 25-km optical fiber segments.
• Demonstrating efficient entanglement swapping to extend entanglement over the combined 50-km channel.
• Calculating system improvements for multi-node entanglement distribution.

Main Results:

• Successfully established entanglement between telecom-wavelength photons at the ends of a 50-km optical channel.
• Demonstrated efficient entanglement swapping between the two fiber segments.
• Calculated system improvements enabling entanglement distribution over 800 km at hertz rates.

Conclusions:

• The presented trapped-ion quantum repeater node is a viable building block for quantum networks.
• The technology offers a near-term path towards distributed networks of quantum sensors, atomic clocks, and quantum processors.
• Efficient entanglement distribution over extended distances is achievable with this approach.