Empirical Falsification of Pairwise-Only Explanations for an Engineered Parity Benchmark on a 133-Qubit Superconducting Processor

Quantum Physics [Submitted on 20 Mar 2026] Empirical Falsification of Pairwise-Only Explanations for an Engineered Parity Benchmark on a 133-Qubit Superconducting Processor Petr Sramek Scalable quantum characterization and error-mitigation workflows often rely on the assumption that relevant device noise and readout contamination can be adequately captured by low-weight, predominantly pairwise interactions. We report a compact hardware experiment designed to operationally distinguish pairwise-only explanations from irreducible triplet-order predictive structure. The A1/A1b protocol implements a parity-structured binary label on a 133-qubit IBM superconducting processor (ibm_torino) and analyzes the resulting data through a classical M"obius decomposition of subset mutual informations. In the A1 baseline, we observe a macroscopic triplet correlation of f(123) = 0.72609 bits (p <= 1.0e-4, permutation floor). In the strict A1b loophole-reduction follow-up, role-symmetry averaging sharply suppresses singleton leakage, modestly reduces pairwise mismatch, and preserves a large irreducible triplet term of f(123) = 0.56521 bits. Crucially, a principled pairwise maximum-entropy baseline consistent with the empirical 1- and 2-body marginals implies only f(123) ~ 6.6e-6 bits, in strong contradiction with the observed hardware data. On A1b, a classifier built exclusively from pairwise features reaches only 0.617 held-out accuracy (chance 0.5), whereas a triplet-inclusive model reaches 0.910. These results provide a concise, open-data demonstration that pairwise benchmarking proxies can be fundamentally blind to higher-order contextual structure in present-day superconducting experiments. Comments: 5 pages, 2 tables. Executed on IBM Quantum (ibm_torino). Open-source Qiskit reproducibility artifacts available via Zenodo Subjects: Quantum Physics (quant-ph) Cite as: arXiv:2603.20542 [quant-ph]   (or arXiv:2603.20542v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2603.20542 Focus to learn more Submission history From: Petr Sramek [view email] [v1] Fri, 20 Mar 2026 22:24:41 UTC (8 KB) Access Paper: HTML (experimental) view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-03 References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)