QECTOR Blog Field notes on quantum error correction, decoder algorithms, qLDPC, noise models, evidence, systems, and ecosystem integration. https://qector.store/feed.xml 2026-08-19T00:00:00Z Guillaume Lessard https://qector.store/guillaume-lessard/ admin@qector.store QECTOR site https://qector.store/images/logo.png Stim, Sinter, PyMatching, and Qiskit Integration https://qector.store/blog/20EcosystemIntegration/ 2026-08-01T00:00:00Z Connect QECTOR to common quantum software workflows while preserving detector, observable, and noise contracts. Shipping a QEC Decoder Responsibly https://qector.store/blog/19ReleaseLicensing/ 2026-08-01T00:00:00Z API stability, wheels, offline licensing, release gates, and the difference between local and network deployment. Rust, PyO3, and QEC Memory Discipline https://qector.store/blog/18RustPyo3Architecture/ 2026-08-01T00:00:00Z FFI buffers, selective repacking, GIL release, Rayon worker state, and memory metrics at the Python boundary. Reproducible QEC Benchmarks https://qector.store/blog/17ReproducibleBenchmarks/ 2026-08-01T00:00:00Z Separate correctness from performance and make every benchmark claim traceable to an artifact and hash. Choosing a Decoder From the Matrix https://qector.store/blog/16DecoderSelection/ 2026-08-01T00:00:00Z A practical decision guide for graphlike, qLDPC, space-time, streaming, CSS, and batch workloads. Logical Error Rates Without the Wrong Metric https://qector.store/blog/15LogicalErrorRates/ 2026-08-01T00:00:00Z Score observables, compute Wilson intervals, keep noise models comparable, and report reproducible LERs. Weighted Decoding and Likelihood Priors https://qector.store/blog/14WeightedDecoding/ 2026-08-01T00:00:00Z Why log((1-p)/p) belongs in the graph and how matching, Union-Find, and space-time paths use weights. Detector Error Models from Faults to Graphs https://qector.store/blog/13DemPipeline/ 2026-08-01T00:00:00Z Parse DEMs, classify hyperedges, collapse parallel mechanisms, set weights, and preserve observables. Rotated Surface Code d=3 https://qector.store/blog/12RotatedSurfaceD3/ 2026-08-01T00:00:00Z Nine data qubits, boundaries, graphlike eligibility, logical strings, and a complete structural audit. A Hand-Worked Steane Decode https://qector.store/blog/11SteaneWorkedDecode/ 2026-08-01T00:00:00Z Compute a Steane syndrome by hand and see why stabilizer cosets matter more than raw correction equality. Evidence-First QEC Architecture and Benchmarks https://qector.store/blog/10BenchmarksArchitecture/ 2026-08-01T00:00:00Z The v1.0.0 backend map, logical scoring, Wilson intervals, metadata, release gates, and claim boundaries. GPU Batch Decoding and Tested Bit Identity https://qector.store/blog/09GpuAcceleration/ 2026-08-01T00:00:00Z Per-shot GPU state isolation, deterministic Union-Find, scoped CPU/GPU identity, and deployment gates. Routing, Cascades, and Two-Stage CSS Decoding https://qector.store/blog/08AutoDecoderCascade/ 2026-08-01T00:00:00Z Structural backend eligibility, fallback verification, hybrid acceptance, and CSS sector feedforward. Space-Time Decoding with Noisy Measurements https://qector.store/blog/07SpaceTimeDecoder/ 2026-08-01T00:00:00Z Detector differencing, temporal and spatial weights, measurement glitches, and streaming scope. Ambiguity Clustering and Learned Predecoders https://qector.store/blog/06AmbiguityGnnNeural/ 2026-08-01T00:00:00Z Freeze confident qubits, solve ambiguous components, and add learned priors without moving the correctness proof. BP-OSD for qLDPC Hypergraphs https://qector.store/blog/05BpOsdQldpc/ 2026-08-01T00:00:00Z Log-domain belief propagation, ordered statistics, residual GF(2) solving, and faithful non-graphlike decoding. UF-01: Parity, Peeling, and Graphlike Decoding https://qector.store/blog/04FastUnionFind/ 2026-08-01T00:00:00Z Cluster parity, spanning-forest peeling, weighted growth, zero-allocation structure, and domain boundaries. Sparse Blossom and Event-Driven Growth https://qector.store/blog/03SparseBlossomEventDriven/ 2026-08-01T00:00:00Z Region states, collision times, tight edges, radix heaps, and the tested scope of Sparse Blossom. Exact Blossom Decoding for Graphlike QEC https://qector.store/blog/02BlossomMwpmExact/ 2026-08-01T00:00:00Z How weighted MWPM, Edmonds' primal-dual view, path boundaries, and sparse candidate escalation fit together. Syndrome Faithfulness: The Decoder Contract https://qector.store/blog/01QecFoundations/ 2026-08-01T00:00:00Z The GF(2) invariant Hc=s, logical cosets, degeneracy, and graphlike eligibility explained from first principles.