Heralded quantum repeater based on the scattering of photons off single emitters using parametric down-conversion...

Area of Science:

• Quantum Information Science
• Quantum Communication Technology
• Solid-State Quantum Systems

Background:

• Quantum repeaters are essential for long-distance quantum communication and information processing.
• Current quantum repeater schemes face challenges in fidelity and scalability.
• Heralded quantum repeaters offer a promising avenue for robust quantum networks.

Purpose of the Study:

• To investigate the feasibility of a heralded quantum repeater based on photon scattering from single emitters in 1D waveguides.
• To design quantum circuits for entanglement generation, swapping, and purification within this framework.
• To assess the practical implementation of these protocols using current experimental capabilities.

Main Methods:

• Designing compact quantum circuits for key quantum repeater functionalities.
• Utilizing parametric down-conversion sources instead of ideal single-photon sources.
• Analyzing protocols for fault tolerance by detecting photon polarization.

Main Results:

• Demonstrated a design for a heralded quantum repeater using waveguide-coupled single emitters.
• Developed protocols for nonlocal entanglement generation, swapping, and purification.
• Achieved theoretical 100% fidelity by converting faulty events into polarization detection.

Conclusions:

• The proposed heralded quantum repeater scheme is attractive, scalable, and realizable with artificial solid-state quantum systems.
• The use of parametric down-conversion sources and polarization detection enhances robustness.
• This approach holds significant potential for advancing long-distance quantum communication networks.