{
  "abstract": "Achieving and quantifying ultrastrong magnon-magnon coupling (USC) remains a key challenge for quantum magnonics. Here, we demonstrate widely tunable USC between chiral (right- and left-handed) and acoustic or optical magnon modes in the van der Waals antiferromagnet $CrPS_4$. Using a full quantum model, we decompose the interaction into three microscopic interaction channels: the co-rotating term $g_1$ (mode hybridization), the counter-rotating term $g_2$ (two-mode squeezing), and, uniquely in the chiral regime, the self-squared term $g_3$ that mediates single-mode squeezing. The normalized coupling ratio reaches $g/f_g$ $\\sim$ 0.41, entering the USC regime. Most significantly, we establish a complete protocol linking these USC parameters to a measurable quantum phenomenon: a squeezed magnon vacuum state. Our simulations not only visualize the chirality and polarization evolution of the hybrid modes but also demonstrate how to directly extract quadrature fluctuations and a substantial squeezing factor (up to $\\sim$ 9.7 dB) from thermal noise-driven magnetization dynamics. This work provides a material-specific quantum framework for USC and a practical pathway to detect and exploit non-classical magnon states in low-damping two-dimensional magnets, opening a route toward quantum-enhanced spintronics and hybrid quantum information platforms.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.11859",
  "author_total": 9,
  "authors": [
    {
      "name": "Xiao Xiao"
    },
    {
      "name": "Zishuang Li"
    },
    {
      "name": "Zui Tao"
    },
    {
      "name": "Lina Chen"
    },
    {
      "name": "Ping Liu"
    },
    {
      "name": "Shuai Zhang"
    },
    {
      "name": "Haozhe Wang"
    },
    {
      "name": "Yong Pu"
    },
    {
      "name": "Ronghua Liu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3fmjc9t5k5506.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.11859",
  "fulltext_url": null,
  "id": "3fmjc9t5k5506",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.11859",
  "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.mes-hall"
    ],
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Mechanical and Optical Resonators"
    ]
  ],
  "openalex": "W7221174369",
  "pdf_url": "https://arxiv.org/pdf/2610.11859",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3fmjc9t5k5506.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.11859",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.11859"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mes-hall",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Tunable Ultrastrong Magnon-Magnon Coupling and Squeezed States in a Triaxial Van der Waals Antiferromagnet",
  "title_text": "Tunable Ultrastrong Magnon-Magnon Coupling and Squeezed States in a Triaxial Van der Waals Antiferromagnet",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:54Z",
  "url": "https://research.draconitic.com/paper/3fmjc9t5k5506",
  "venue": "arXiv",
  "versions": []
}