{
  "abstract": "Performing measurements on gapless quantum ground states can give rise to new universal phenomena, whose origins remain poorly understood even for the paradigmatic Ising critical point. Replica methods offer a natural framework to study such post-measurement ensembles, with the replica limit $Q\\to 1$ describing physical Born-averaged observables. Here we show that, for the monitored critical Ising chain, the replicated post-measurement ensemble of states itself undergoes a phase transition precisely at the physically relevant replica limit $Q \\to 1$, preventing standard replica treatments. We use boundary conformal field theory (BCFT) methods to explain the underlying mechanism of this transition. Our methods yield a perturbative analytic calculation of the universal $O(1)$ constant in the Shannon entropy of the measurement record, previously known only numerically. We also apply our tools to study measurement-averaged spin correlators, providing a unified description of the universal properties of measurement outcomes and post-measurement states in the critical Ising chain.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.13802",
  "author_total": 3,
  "authors": [
    {
      "name": "Kabir Khanna"
    },
    {
      "name": "Sara Murciano"
    },
    {
      "name": "Romain Vasseur"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2gytk96160ta9.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.13802",
  "fulltext_url": null,
  "id": "2gytk96160ta9",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.13802",
  "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",
      "cond-mat.stat-mech"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Quantum many-body systems"
    ]
  ],
  "openalex": "W7221568564",
  "pdf_url": "https://arxiv.org/pdf/2610.13802",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2gytk96160ta9.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:28:36Z",
      "native_id": "2610.13802",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.13802"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.stat-mech",
      "subfield": "statistical-nonlinear"
    }
  ],
  "title": "Replica Transition at Measurement-Altered Ising Criticality",
  "title_text": "Replica Transition at Measurement-Altered Ising Criticality",
  "type": "preprint",
  "updated_at": "2026-10-30T12:28:36Z",
  "url": "https://research.draconitic.com/paper/2gytk96160ta9",
  "venue": "arXiv",
  "versions": []
}