{
  "abstract": "We present a Hermitian squeezing-Dicke model as a minimal closed-system setting for non-Hermitian many-body physics. Squeezing generates an effective parity-time ($\\mathcal{PT}$) symmetry and exchanges gainy and lossy eigenmodes without dissipation. We identify an anomalous dynamical superradiant phase (DSRP) that exhibits by a mean-field superradiant order in the $\\mathcal{PT}$ symmetry-breaking regime, accompanied by a $\\mathbb{Z}_2$-symmetry-breaking ground-state quantum phase transition. Additionally, it undergoes a $\\mathcal{PT}$-breaking dynamical phase transition at an exceptional point (EP). The excitation energy vanishes near both boundaries, giving critical slowing down. The vacuum photon number is divergent at the ground-state transition but is finite and nonanalytic at the EP, distinguishing the DSRP from the conventional superradiant phase and from a standard dynamical instability. Squeezing causes the coupling phase to act as an artificial magnetic flux, which yields flux-controlled nonreciprocal quantum amplification in the DSRP. Our results offer an alternative pathway to non-Hermitian many-body physics and nonreciprocal quantum amplification in closed Hermitian systems.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.26770",
  "author_total": 4,
  "authors": [
    {
      "name": "You-Qi Lu"
    },
    {
      "name": "Jun-Ling Wang"
    },
    {
      "name": "Qing-Hu Chen"
    },
    {
      "name": "Yu-Yu Zhang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3wma85gj5kxsp.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.26770",
  "fulltext_url": null,
  "id": "3wma85gj5kxsp",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.26770",
  "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",
      "3107|Quantum Mechanics and Non-Hermitian Physics"
    ]
  ],
  "openalex": "W7166081170",
  "pdf_url": "https://arxiv.org/pdf/2606.26770",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3wma85gj5kxsp.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:14Z",
      "native_id": "2606.26770",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.26770"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Non-Hermiticity of an anomalous superradiant phase",
  "title_text": "Non-Hermiticity of an anomalous superradiant phase",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:50Z",
  "url": "https://research.draconitic.com/paper/3wma85gj5kxsp",
  "venue": "arXiv",
  "versions": []
}