FusionQ: A Generic and Optimal Decoding Framework for Ultra-Low-Latency Quantum Error Correction

arXiv:2611.13111v1 Announce Type: new Abstract: Quantum error correction (QEC) decoding has traditionally been organized around fixed decoding instances: a monolithic space-time detector error model (DEM), or a predetermined temporal window, is handed to a backend decoder after enough syndrome data has arrived. This paper presents FusionQ, a fusion decoding framework that changes this paradigm by deriving local decoding tasks from the observed syndrome and then fusing their results into a single global correction. Instead of forcing every shot through the same global or windowed problem, FusionQ builds open-boundary local DEMs around fired detector clusters and expands the corresponding footprints only when a local optimum uses virtual boundary errors.