{
  "abstract": "Magic state cultivation prepares high-fidelity magic states at low expected space-time costs; however, the exact performance of some schemes is unsettled due to the difficulty in simulating non-Clifford circuits. Here, we use matrix-product states (MPS) based methods to compute the exact performance of two types of fold-transversal cultivation schemes: (i) the Sahay et al method based on the regular surface code S gate, and (ii) a method we propose based on a partially fault-tolerant fold-transversal S gate. We show that for the former protocol at $d=5$, the $|T\\rangle$ output reaches similar logical error rates to the $|S\\rangle$ output, traditionally used as a cheap full Clifford proxy. This contrasts with the $\\sim10\\times$ discrepancy reported for the $d=5$ colour-code scheme of Gidney et al. We also find that our new $d=5$ scheme has $\\sim1.3\\times$ lower expected space-time cost while still reaching $10^{-9}$ logical error rate. We show that MPS and Clifford-augmented MPS (CAMPS) perform on par with or even better than the recently introduced near-Clifford simulator Clifft on the hardest $d=5$ regular surface code scheme. Additionally, to speed up simulation, we propose a new pre-screening method based on simple Pauli propagation, lowering by up to three orders of magnitude the required number of exact simulations, and use several simulator-agnostic sampling methods such as subset sampling.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.19116",
  "author_total": 2,
  "authors": [
    {
      "name": "Tom Hartweg"
    },
    {
      "name": "Asier Piñeiro Orioli"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7vf09j7d7dmv0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.19116",
  "fulltext_url": null,
  "id": "7vf09j7d7dmv0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.19116",
  "language": null,
  "licence": "CC-BY-NC-SA-4.0",
  "licence_label": "CC BY-NC-SA 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-sa/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Computing Algorithms and Architecture"
    ]
  ],
  "openalex": "W7213512124",
  "pdf_url": "https://arxiv.org/pdf/2609.19116",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-16",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7vf09j7d7dmv0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:01Z",
      "native_id": "2609.19116",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.19116"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Comparing magic state cultivation methods using matrix product states",
  "title_text": "Comparing magic state cultivation methods using matrix product states",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:01Z",
  "url": "https://research.draconitic.com/paper/7vf09j7d7dmv0",
  "venue": "arXiv",
  "versions": []
}