{
  "abstract": "We give a polynomial-time classical algorithm which samples from the syndrome distribution of a surface code state corrupted by coherent nearest-neighbor $ZZ$ crosstalk. Our algorithm complements the known efficient simulation algorithms for coherent single-qubit errors in the surface code. When both single-qubit coherent noise and coherent crosstalk are present, we find a complexity-theoretic obstruction to efficient simulation: unless the polynomial hierarchy collapses, there is no efficient classical algorithm for sampling from the syndrome distribution, even up to a constant multiplicative error. This is obtained by connecting the syndrome distribution under coherent noise to the output distribution of certain IQP circuits associated with a non-planar graph.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.40279",
  "author_total": 3,
  "authors": [
    {
      "name": "Andrew S. Darmawan"
    },
    {
      "name": "Yelyzaveta Kolesnyk"
    },
    {
      "name": "Robert Koenig"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8es7xd45v0bcf.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.40279",
  "fulltext_url": null,
  "id": "8es7xd45v0bcf",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.40279",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Computing Algorithms and Architecture"
    ]
  ],
  "openalex": "W7215084495",
  "pdf_url": "https://arxiv.org/pdf/2609.40279",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8es7xd45v0bcf.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:49Z",
      "native_id": "2609.40279",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.40279"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Classical simulation of coherent crosstalk in surface codes",
  "title_text": "Classical simulation of coherent crosstalk in surface codes",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:49Z",
  "url": "https://research.draconitic.com/paper/8es7xd45v0bcf",
  "venue": "arXiv",
  "versions": []
}