{
  "abstract": "Phase stiffness governs macroscopic quantum coherence in superfluids and superconductors, providing a sensitive probe of condensate depletion, fluctuations, and phase transitions. However quantitative and spatially resolved measurements remain challenging. Here we report a contactless, local, all-optical measurement of superconducting phase stiffness using propagating antiferromagnetic magnons as remote sensors. In CrSBr, strong exciton-magnon coupling enables optical excitation and detection of magnon wavepackets and precise determination of their group velocity. When CrSBr is interfaced with underdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$, we find that the magnon group velocity is substantially enhanced below the superconducting transition and quantitatively encodes the phase stiffness through Meissner screening currents. Using this capability, we identify a parallel-field-induced Berezinskii-Kosterlitz-Thouless transition through direct observation of the universal phase-stiffness jump, revealing a field-controlled route to expose intrinsic two-dimensional phase-ordering physics in a bulk cuprate. Our work establishes propagating magnons as local probes of superconducting electrodynamics and phase-coherent phenomena in low-dimensional quantum materials.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.08934",
  "author_total": 17,
  "authors": [
    {
      "name": "Yue Sun"
    },
    {
      "name": "Mai Nguyen"
    },
    {
      "name": "Naiyuan James Zhang"
    },
    {
      "name": "Dingbin Huang"
    },
    {
      "name": "Shuai Yuan"
    },
    {
      "name": "Aljoscha Söll"
    },
    {
      "name": "Arun Ramanathan"
    },
    {
      "name": "Takashi Taniguchi"
    },
    {
      "name": "Kenji Watanabe"
    },
    {
      "name": "Xavier Roy"
    },
    {
      "name": "Zdeněk Sofer"
    },
    {
      "name": "Shigeyuki Ishida"
    },
    {
      "name": "Hiroshi Eisaki"
    },
    {
      "name": "Makoto Hashimoto"
    },
    {
      "name": "Zhi-Xun Shen"
    },
    {
      "name": "Joseph Orenstein"
    },
    {
      "name": "Xiaodong Xu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ec7tgt1w4atm3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.08934",
  "fulltext_url": null,
  "id": "ec7tgt1w4atm3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.08934",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.str-el"
    ],
    [
      "arxiv",
      "cond-mat.supr-con"
    ],
    [
      "openalex",
      "3104|Physics of Superconductivity and Magnetism"
    ]
  ],
  "openalex": "W7220914396",
  "pdf_url": "https://arxiv.org/pdf/2610.08934",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-06",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ec7tgt1w4atm3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:37Z",
      "native_id": "2610.08934",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.08934"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Remote magnon sensing detects the universal phase stiffness jump in Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$",
  "title_text": "Remote magnon sensing detects the universal phase stiffness jump in Bi_2Sr_2CaCu_2O_8+δ",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:37Z",
  "url": "https://research.draconitic.com/paper/ec7tgt1w4atm3",
  "venue": "arXiv",
  "versions": []
}