PARALLEL DECODING FOR QUANTUM ERROR CORRECTING CODES

Methods, systems, and apparatus for parallel decoding for quantum error correction codes. In one aspect, a classical computer system is configured to implement a decoding process on measurement data received from a quantum computing system to determine errors in a quantum computation. The classical computing system implements a main thread, multiple worker threads, and a data structure common to each worker thread. The data structure stores data of a dynamic system of disjoint clusters of nodes of a detector graph for the decoding process, where the data includes compressed logical flip information of child nodes in each cluster of nodes. During execution of the decoding process, the multiple worker threads are configured to, in parallel: obtain clusters of nodes and modify the clusters of nodes, where, for each modification, the worker thread updates data in the data structure that corresponds to the cluster under an atomicity primitive.