IBM publishes gross-code qLDPC memory in Nature

IBM/Starling fault-tolerant roadmap

IBM described a quantum error-correction memory built on low-density parity-check (qLDPC) codes with a 0.7% error threshold, matching the surface code. The system showed 12 logical qubits could be preserved for nearly a million cycles with 288 physical qubits, compared to nearly 3,000 for a surface-code approach.

• qLDPC codes achieve 0.7% error threshold, matching surface code performance.
• 12 logical qubits preserved for ~1 million cycles with only 288 physical qubits.
• Surface code would require nearly 3,000 physical qubits for equivalent 12-qubit memory—qLDPC is 10x more efficient.
• Published in Nature; demonstrates path to scaling quantum computers with fewer physical qubits.