{
  "abstract": "The laboratory-frame anti-Jaynes--Cummings (AJC) interaction retains a residual detuning $2fλ$ that is absent from the rotating-frame model. We map two proposed remedies---a Kerr shift $χ(\\hat a^\\dagger\\hat a)^2$ and collective Dicke coupling of $N$ two-level emitters---for a squeezed vacuum on that ladder ($r=1$, $\\langle n\\rangle=\\sinh^2 r\\simeq 1.38$). All quoted contrasts are the amplitude of the first turning point of the atomic ground-state population, which coincides with the two-level formula $\\mathcal{C}=1/[1+(2f+χ)^2]$ at $r=0$ to $10^{-9}$. Three results follow. (i)~A single Kerr strength never restores unit contrast at $r=1$; the $r=0$ $n$-dependent shift $χ(2n+1)$ cannot cancel $2fλ$ on every occupied Fock component. (ii)~The exact $r=1$ contrast at $χ=0$ is not reproduced by an incoherent sum $\\sum_n P_n(r)\\,\\mathcal{C}_n$ built from the $r=0$ two-level formula; pointwise deviations are several tenths. (iii)~Collective coupling raises the contrast systematically. At $f=5$ one finds $\\mathcal{C}=0.140$ ($N=1$) and $\\mathcal{C}=0.575$ ($N=8$), above the unsqueezed value $8/[8+(2f)^2]=0.074$. The $N=16$ point at this $f$ remains truncation-limited and is not quoted to three digits. The same $N\\sim(2f)^2$ estimate for $\\mathcal{C}=1/2$ places trapped-ion values $f\\sim 10^{2}$--$10^{3}$ outside the present construction. The relevant platform is ultrastrong circuit QED with $f\\sim 1$--$10$. The calculation is a numerical control landscape, not a new solvable limit.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.04580",
  "author_total": 1,
  "authors": [
    {
      "name": "Onyango Stephen Okeyo"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/enbfademnnm2g.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.04580",
  "fulltext_url": null,
  "id": "enbfademnnm2g",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.04580",
  "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 optics and atomic interactions"
    ]
  ],
  "openalex": "W7211887451",
  "pdf_url": "https://arxiv.org/pdf/2609.04580",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/enbfademnnm2g.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:14Z",
      "native_id": "2609.04580",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.04580"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Residual detuning in the laboratory-frame anti-Jaynes--Cummings model with a squeezed vacuum",
  "title_text": "Residual detuning in the laboratory-frame anti-Jaynes--Cummings model with a squeezed vacuum",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:14Z",
  "url": "https://research.draconitic.com/paper/enbfademnnm2g",
  "venue": "arXiv",
  "versions": []
}