Constant-Overhead Fault-Tolerant Bell-Pair Distillation Using High-Rate Codes

Area of Science:

• Quantum Information Science
• Quantum Error Correction
• Quantum Computing

Background:

• Bell-pair distillation is crucial for quantum communication and computation.
• Previous methods often incur significant overhead or complexity.
• Near-term quantum devices require efficient and fault-tolerant protocols.

Purpose of the Study:

• To present a novel fault-tolerant Bell-pair distillation scheme.
• To achieve constant overhead and high distillation rates.
• To enable direct use of distilled Bell pairs in distributed quantum applications.

Main Methods:

• Utilizing high-rate quantum low-density parity-check (qLDPC) codes.
• Implementing a fault-tolerant distillation circuit.
• Performing full circuit-level analysis for fault-tolerance.

Main Results:

• Achieved a constant distillation rate equal to the qLDPC code rate.
• Demonstrated fault-tolerance for Bell-pair infidelities below ~10%.
• Eliminated unencoding overhead by keeping Bell pairs encoded in qLDPC codes.

Conclusions:

• qLDPC-based distillation offers a practical and resource-efficient route.
• The scheme is compatible with near-term quantum capabilities.
• Enables direct integration into distributed quantum networks and computing.