Spatially Coupled MacKay-Neal/Hsu-Anastasopoulos CSS Codes Achieve the Quantum-Erasure Hashing Bound by Seeded BP Decoding
Quantum error correction codes that match theoretical limits using practical algorithms
Researchers proved that a specific type of quantum error-correction code, when combined with a spatial coupling technique and a particular decoding algorithm, can reach the theoretical performance limit for correcting erasure errors. The breakthrough shows that this practical decoding method works as well as the best theoretically possible method, closing a gap between theory and what's actually implementable.
Quantum computers need extremely reliable error correction to function at scale, and current codes waste capacity by not reaching their theoretical limits. This work demonstrates that a practical decoding algorithm can achieve optimal performance, potentially reducing the number of physical qubits needed to run a quantum computation and making quantum computers more feasible to build.