This dataset and code repository accompanies the publication introducing BA-QEC, the first quantum-error-correction decoder explicitly inspired by biological immune-system architecture. BA-QEC integrates a Bayesian prior derived from human TCRβ CDR3 length distributions and an adaptive clonal-expansion memory mechanism to improve decoding performance in topological quantum codes. Simulations of a distance-7 rotated surface code demonstrate 22% threshold improvement from the biological prior alone, and up to 61% enhancement when combined with clonal memory under temporally correlated (1/f-type) noise. All code is open-source (MIT license) and fully reproducible in <10 minutes on Google Colab. The repository includes: Python notebooks for Stim-based and PyMatching-based simulations, Clonal-expansion cache implementation, Scripts for reproducing figures and pseudothreshold plots, Documentation on integrating the biological prior into MWPM decoding. This work establishes a novel link between adaptive immunity and quantum error correction, offering a new paradigm for biologically inspired, efficient, and adaptive decoders.
This dataset and code repository accompanies the publication introducing BA-QEC, the first quantum-error-correction decoder explicitly inspired by biological immune-system architecture. BA-QEC integrates a Bayesian prior derived from human TCRβ CDR3 length distributions and an adaptive clonal-expansion memory mechanism to improve decoding performance in topological quantum codes. Simulations of a distance-7 rotated surface code demonstrate 22% threshold improvement from the biological prior alone, and up to 61% enhancement when combined with clonal memory under temporally correlated (1/f-type) noise. All code is open-source (MIT license) and fully reproducible in <10 minutes on Google Colab. The repository includes: Python notebooks for Stim-based and PyMatching-based simulations, Clonal-expansion cache implementation, Scripts for reproducing figures and pseudothreshold plots, Documentation on integrating the biological prior into MWPM decoding. This work establishes a novel link between adaptive immunity and quantum error correction, offering a new paradigm for biologically inspired, efficient, and adaptive decoders.
H-ImmQπDecoder v2.0 is a novel, bio-inspired quantum error-correction framework that integrates three unprecedented components inside a unified decoding architecture: Immune-Inspired Adaptive Memory (v2) — A dynamic artificial immune system that learns, stores, mutates, and generates local correction patterns (“antibodies”) in response to quantum syndrome patterns and π-field structures. Dynamic π-Field Modeling — A hydrodynamic-style coherence field representing spatial quantum stability, noise topology, and turbulence. The π-field evolves over time through diffusion, relaxation, and noise-dependent source terms, acting as an environmental prior for the decoder. Nonlinear Quantum-π Phase Correction (v2) — A continuous phase-stabilization mechanism capable of correcting analog phase drift beyond discrete Pauli operations. It leverages local π-values and phase gradients to compute nonlinear effective corrections. Quantum Metabolism — An internal energy state regulating the decoder’s adaptation intensity, mutation rate, and stress response. This metabolic model introduces relaxed/active/stressed/overloaded states, enabling autonomous self-regulation under strong noise. Together, these components form the world's first Bio-Quantum Error Correction (Bio-QEC) engine — a hybrid organism-like system capable of learning and adapting to correlated, non-Markovian, or topologically structured noise in quantum processors. This repository contains: The full Python implementation of H-ImmQπDecoder v2.0 The dynamic π-field model The artificial immune memory with mutational operators The nonlinear Quantum-π phase correction modules The quantum metabolic engine A toy lattice simulator for testing and experimentation Example scripts for running multi-round decoding experiments Intended audience: Quantum computing researchers, QEC developers, physicists working with correlated noise, AI-inspired algorithm designers, and early-stage quantum hardware engineers. Novelty: To the best of my knowledge, this is the first quantum error decoder that unifies immune-system principles, hydrodynamic coherence modeling, continuous nonlinear phase correction, and metabolic regulation in a single decoding framework. This constitutes a new research direction that I call bio-inspired quantum error correction. Applications: Correlated-noise quantum devices (superconducting qubits, trapped ions) Non-Markovian or drifting qubit environments NISQ-era systems requiring online adaptive decoding Exploratory research in hybrid biological-quantum computation
Abstract Quantum error-correction decoders must convert noisy syndrome records into logical decisions while operating under strict latency and reliability constraints. Minimum-weight perfect matching (MWPM) remains a strong baseline for surface-code decoding because it is fast, interpretable, and exact for its graphlike optimization problem [1–8]. However, the graphlike independent-error approximation can become mismatched when syndrome records contain temporal drift, measurement corruption, crosstalk, bursts, or mixtures of mechanisms [9–18]. We introduce SAGE-QEC, a failure-aware selective decoder that retains nominal PyMatching as its default decision and learns when an observable syndrome structure warrants an alternative candidate. SAGE-QEC uses train-frozen structure thresholds, a candidate ranker, validation-only policy selection, and a paired blind evaluation. Across 45 simulator conditions, SAGE-QEC reduced the aggregate logical error rate from 27.1285% for PyMatching to 24.8320%, corresponding to an 8.47% relative reduction. The campaign used rotated surface-code memory circuits at distances 3, 5, and 7, nominal circuit parameters 0.002, 0.003, and 0.005, five seeds, and four test regimes withheld from training: Burst-3, Temporal Drift, Crosstalk, and Mixed Noise. The test set contained 81,000 paired shots. All twelve distance-by-regime aggregate comparisons favored SAGE-QEC in the executed campaign, with paired bootstrap intervals below zero for SAGE-QEC minus PyMatching. The result is evidence of a reproducible simulator-level improvement, not a claim of universal decoder superiority. SAGE-QEC currently uses logical-output proxy candidates rather than a complete physical correction search, and its intervention rate remains high under distribution shift. It has not yet been compared with a fully calibrated correlated-noise space-time PyMatching baseline or hardware calibration data. We therefore characterize SAGE-QEC as a strong qualification-stage prototype and release a complete audit protocol for the next industrial validation stage.
Noise-induced errors in quantum information processing corrupt computation and cause useful algorithms to fail. Quantum ErrorCorrection (QEC) counteracts this by encoding a single logical qubit across many physical qubits and correcting errors through repeatedsyndrome measurements. The Minimum-Weight Perfect Matching (MWPM) decoder is the accuracy benchmark for surface-codedecoding, but its microsecond-scale latency can consume the entire QEC cycle time of superconducting processors, leaving almost nomargin for other control operations. Pre-decoded lookup tables reduce latency to the nanosecond scale, but their memory requirementsgrow exponentially with code size, limiting them to very small code distances. In this work, we demonstrate a single-level cache,implemented as a software prototype, that accelerates decoding by exploiting the repetitive nature of surface-code syndromes. Hitrates above 80% are achieved for code distances up to 9 at below-threshold noise rates, and effective decoding speedups of up to18.1 times over PyMatching’s standalone decoding time are observed at code distance ≥ 5. Cache lookup latency remains below 400nanoseconds in the worst case, with memory well below that of full lookup tables. We further develop a mathematical frameworkdefining the theoretical limits of any cache-based decoder.
This review article provides a comprehensive overview of recent developments in the field of quantum error correction (QEC), which stands as one of the biggest challenges for quantum computing. The extreme sensitivity of quantum systems to environmental noise makes it difficult to build reliable and scalable quantum computers. Inspired by pioneering codes like those from Shor and Steane, this work discusses the most promising QEC approaches today, particularly topological codes such as surface codes and low-density parity-check (LDPC) codes. The paper delves into critical experimental successes from industry leaders like Google, IBM, and Quantinuum, including their ”below-threshold” error correction demonstrations and roadmaps for fault-tolerant systems. It also presents a comparative analysis between classical algorithms like Minimum-Weight Perfect Matching (MWPM) and newer, machine learning-based decoder approaches. The discussion section addresses open problems that need to be solved in the future, such as correlated noise, cryogenic control, and the creation of fault-tolerant logical gate sets. This review aims to summarize the current state of the QEC field, serving as a guiding resource for both academics and industry professionals in shaping future research and development strategies.
Quantum error correction (QEC) protects quantum computations by repeatedly measuring stabilizer syndromes and using a classical decoder to infer corrections. Modern surface-code decoders are increasingly calibration-aware: they use recent device behavior to set priors such as matching-graph edge probabilities, and these priors directly shape the selected correction. We identify the prior-update path as an overlooked integrity-critical attack surface: a poisoned prior can change decoding decisions even when the syndrome stream, logical labels, and decoder implementation are unchanged. This makes prior poisoning different from ordinary syndrome anomalies and difficult for raw syndrome-anomaly tests to detect. We introduce PriorGuard, a lightweight semantic guard that checks proposed prior changes on high-influence detector-graph entries against private syndrome-derived evidence, accepts updates only when their log-odds movement is evidence-supported, and otherwise falls back to the last evidence-supported prior. We evaluate on Stim-generated rotated surface-code memory circuits decoded with PyMatching. Prior influence is highly concentrated, with the top 10 percent of entries carrying over 60 percent of positive logical-error influence; poisoning only 6.4 percent of decoder-prior entries can raise logical error rate (LER) by 3.35x. PriorGuard recovers most attack-induced loss with a low false-positive rate and modest update-boundary overhead of about 1.7--1.8 ms and less than 0.31 MB auxiliary memory per update.
Quantum error correction (QEC) is indispensable for the realization of fault-tolerant quantum computers. Surface codes are a leading QEC architecture due to their high error thresholds and planar design. The core challenge lies in the decoding process: inferring latent physical errors from syndrome measurements and applying appropriate corrections. Although there are classical decoders, their performance can degrade with complex noise or be computationally demanding. This paper investigates an advanced Deep Reinforcement Learning (DRL) approach, employing a Dueling Double Deep Q-Network (DQN), to decode X-type Pauli errors on ad=3rotated surface code. The DRL agent leverages syndrome history to discern temporal error correlations and utilizes a multi-round correction strategy, enabling iterative refinement of corrective actions within an environment that simulates both physical qubit errors and syndrome measurement noise. After 30,000 training episodes with a 5 % physical error rate and 1 % measurement noise, the agent achieved a 0.00 % logical error rate in the extended test, an average episode reward of 0.38, and successfully cleared syndromes in 63 % of the test cases, demonstrating robust learning of a safe decoding policy. The persistent challenge of high training loss, despite good policy performance, is discussed, offering insights into value function approximation in complex QEC environments.