{
  "abstract": "Here we demonstrate quantum--classical break-even for chemical dynamics applications, reaching useful accuracy with a quantum-hardware wall-clock time comparable to that estimated for practical classical computing resources. To this end, we develop a workflow for problems that are hardware-native but classically hard. We target large ring-shaped molecules that map naturally onto quantum hardware with neighboring connections. Exploiting the spatial locality of interactions, we compress short-time evolution within a small region using tensor networks. We then use rotational symmetry to replicate the compressed circuit in space and time, enabling long-time dynamics of large systems with practical classical processing times. We apply the workflow to conjugated macrocycles with rotational periodicity, 12-qubit benzene and 120-qubit [60]annulene, by embedding their electronic structure onto loops of IBM quantum processors. For the annulene, we compared the quantum-processing-unit (QPU) wall-clock times for hole-doped nonequilibrium dynamics to the estimated wall-clock time of two state-of-the-art classical methods, Majorana propagation and matrix-product-state time evolution based on the time-dependent variational principle. We show a situation in which a hybrid quantum--classical strategy is comparable to a classical-only counterpart in terms of both accuracy and computational time for a conventional high-performance computing system under ideal parallelization. These results show that quantum hardware can become a realistic computational option for chemical simulations for practitioners in chemical science and engineering.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.39693",
  "author_total": 8,
  "authors": [
    {
      "name": "Shu Kanno"
    },
    {
      "name": "Kenji Sugisaki"
    },
    {
      "name": "Takashi Imamichi"
    },
    {
      "name": "Toshinari Itoko"
    },
    {
      "name": "Rei Sakuma"
    },
    {
      "name": "Hajime Nakamura"
    },
    {
      "name": "Qi Gao"
    },
    {
      "name": "Naoki Yamamoto"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7zwmzjpc14t8y.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.39693",
  "fulltext_url": null,
  "id": "7zwmzjpc14t8y",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.39693",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Computing Algorithms and Architecture"
    ]
  ],
  "openalex": "W7215077094",
  "pdf_url": "https://arxiv.org/pdf/2609.39693",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7zwmzjpc14t8y.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:52Z",
      "native_id": "2609.39693",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.39693"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Quantum--classical break-even in electronic dynamics of macrocyclic molecules",
  "title_text": "Quantum--classical break-even in electronic dynamics of macrocyclic molecules",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:41Z",
  "url": "https://research.draconitic.com/paper/7zwmzjpc14t8y",
  "venue": "arXiv",
  "versions": []
}