{
  "abstract": "We present a partially fault-tolerant implementation of QAOA based on the $[[4,2,2]]$ error-detection code, targeting the Max-Cut problem on a square graph. Our main contribution is a novel ancilla-mediated logical $R_{ZZ}$ gate enabling interactions between qubits in different $[[4,2,2]]$ blocks. We evaluate unencoded and encoded circuits under five noise models, with both all-to-all and grid-routed connectivity, using the Cirq and qsimcirq frameworks with parallel CPU execution. Post-selection on stabilizer measurements consistently improves the probability of sampling optimal bitstrings, with five measurements providing the strongest benefit. These results support error-detection as a practical near-term strategy for improving the quality of variational quantum algorithms.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.07537",
  "author_total": 5,
  "authors": [
    {
      "name": "Matteo Robert Child"
    },
    {
      "name": "Emanuele Dri"
    },
    {
      "name": "Giacomo Vitali"
    },
    {
      "name": "Chiara Vercellino"
    },
    {
      "name": "Alberto Leporati"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4ectcyax74kgz.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.07537",
  "fulltext_url": null,
  "id": "4ectcyax74kgz",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.07537",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cs.ET"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Computing Algorithms and Architecture"
    ]
  ],
  "openalex": "W7212056879",
  "pdf_url": "https://arxiv.org/pdf/2609.07537",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4ectcyax74kgz.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2609.07537",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.07537"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Toward Fault-Tolerant Variational Optimization: QAOA under [[4,2,2]] Error Detection",
  "title_text": "Toward Fault-Tolerant Variational Optimization: QAOA under [[4,2,2]] Error Detection",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/4ectcyax74kgz",
  "venue": "arXiv",
  "versions": []
}