IonQ reports single-CPU decoding for simulated quantum circuits

IonQ researchers report that a standard CPU decoded errors in simulated quantum circuits representing up to 408 logical qubits and more than 31.5 million operations. Their paper says the decoding added as little as 0.02 percent to the circuits' running time. The system uses a sliding-window decoder and memory optimizations to run multiple decoding tasks on 12 cores of one CPU. Decoding interprets error signals so a quantum computer can correct faults while continuing its work. The reported scale comes from benchmark circuits, rather than a physical quantum computer operating with hundreds of logical qubits.