{
  "abstract": "More than two decades ago, Bennett \\emph{et al.} [Phys. Rev. A \\textbf{59}, 1070 (1999)] asked whether perfect local discrimination of orthogonal quantum states can require more than two copies. This question was subsequently answered for adaptive protocols that process the copies separately [Phys. Rev. Lett. \\textbf{126}, 210505 (2021)], but remained open when each laboratory is allowed to process its local copies collectively. Here we resolve this stronger setting and identify collective access across repeated local inputs as a distinct resource. For every fixed odd-prime local dimension, there exist complete maximal-stabilizer eigenbases whose copy complexity under individual-copy separable measurements diverges with system size. Under collective processing this behavior changes sharply: every maximal-stabilizer eigenbasis in odd-prime local dimension is perfectly decoded by one-round collective LOCC using at most three copies. Collective processing, however, does not remove multicopy hardness in general. For every fixed local dimension $d\\ge2$, we prove the existence, within an explicit phase family, of complete bases whose copy complexity remains unbounded even under collective separable measurements, with a square root of the number of subsystems as lower-bound scale. Thus sample number, spatial measurement power, and coherent access across repeated local inputs are distinct resources in distributed quantum measurement.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.07233",
  "author_total": 3,
  "authors": [
    {
      "name": "Mao-Sheng Li"
    },
    {
      "name": "Yan-Ling Wang"
    },
    {
      "name": "Zhu-Jun Zheng"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/czvhkn5d3av6n.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.07233",
  "fulltext_url": null,
  "id": "czvhkn5d3av6n",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.07233",
  "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 Information and Cryptography"
    ]
  ],
  "openalex": "W7212052233",
  "pdf_url": "https://arxiv.org/pdf/2609.07233",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/czvhkn5d3av6n.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:48Z",
      "native_id": "2609.07233",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.07233"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Power and Limits of Collective Local Measurements in Multicopy State Discrimination",
  "title_text": "Power and Limits of Collective Local Measurements in Multicopy State Discrimination",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:48Z",
  "url": "https://research.draconitic.com/paper/czvhkn5d3av6n",
  "venue": "arXiv",
  "versions": []
}