Measurement-Based Entanglement Distillation and Constant-Rate Quantum Repeaters over Arbitrary Distances

Area of Science:

• Quantum Information Science
• Quantum Communication
• Quantum Computing

Background:

• Measurement-based quantum repeaters are crucial for long-distance quantum communication.
• They rely on entanglement distillation and swapping using resource states and Bell measurements.

Purpose of the Study:

• To introduce a systematic protocol for measurement-based entanglement distillation.
• To apply this protocol to quantum repeaters, leveraging any stabilizer code.
• To provide insights into resource state noise and strategies for fault-tolerant preservation.

Main Methods:

• Developed a protocol for measurement-based entanglement distillation adaptable to any stabilizer code.
• Defined resource states and derived error-recovery operations based on Bell measurement outcomes.
• Proposed a measurement-based repeater protocol using quantum low-density parity-check (QLDPC) codes.

Main Results:

• Demonstrated constant-yield Bell state distribution over arbitrary distances using QLDPC codes.
• Identified a fault-tolerant threshold for physical errors within repeater segments.
• Showed that increasing QLDPC code size suppresses logical errors while maintaining encoding rate.

Conclusions:

• Established a scalable backbone for global-scale fault-tolerant quantum networks.
• The proposed protocol offers deeper insights into repeater performance and error management.
• This work paves the way for robust and efficient quantum communication infrastructure.