{
  "abstract": "Multiphoton indistinguishability is a key resource for photonic quantum technologies, yet its characterization typically relies on resource-intensive methods. In this work, we develop two efficient and experimentally friendly protocols to estimate or bound the fidelity $F_{\\mathrm{ind}}$ of an $N$-photon state to the closest perfectly indistinguishable state. The first protocol applies to sources preparing separable states, uses a single Fourier interferometer together with photon-number-resolving detection, and yields tight two-sided bounds on $F_{\\mathrm{ind}}$. The second protocol combines randomized implementations of linear-optical interferometers with photon counting, enabling direct estimation of $F_{\\mathrm{ind}}$ for arbitrary $N$-photon states. Both protocols can certify $F_{\\mathrm{ind}} = 1 - \\mathcal{O}(ε)$ using provably optimal $\\mathcal{O}(1/ε)$ samples, in contrast to previous approaches which required prior assumptions on the model of partial distinguishability. Our methods, based on a multiphoton generalization of the Hong-Ou-Mandel test, bring the rigorous and operationally meaningful certification of multiphoton indistinguishability within reach of current photonic technologies.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.37620",
  "author_total": 5,
  "authors": [
    {
      "name": "Marco Robbio"
    },
    {
      "name": "Michał Oszmaniec"
    },
    {
      "name": "Nicolas J. Cerf"
    },
    {
      "name": "Ernesto Galvão"
    },
    {
      "name": "Leonardo Novo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/30v3jg6hgrw68.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.37620",
  "fulltext_url": null,
  "id": "30v3jg6hgrw68",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.37620",
  "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",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Information and Cryptography"
    ]
  ],
  "openalex": "W7214991737",
  "pdf_url": "https://arxiv.org/pdf/2609.37620",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/30v3jg6hgrw68.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.37620",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.37620"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Optimal interferometric certification of multi-photon indistinguishability",
  "title_text": "Optimal interferometric certification of multi-photon indistinguishability",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/30v3jg6hgrw68",
  "venue": "arXiv",
  "versions": []
}