{
  "abstract": "MnF$_2$, the textbook two-sublattice antiferromagnet, has reemerged as a prototypical altermagnet, yet the sublattice-odd exchange that defines this identity remains under active debate: it enters the magnon splitting only in quadrature with the dipole--dipole interaction, its magnitude suppressed and its sign erased. An overdetermined first-principles total-energy mapping resolves this scale as a seventh-neighbor imbalance $δ{J_7}\\simeq+8~μ$eV. The resulting Hamiltonian, with the dipole--dipole interaction included explicitly, reproduces the low-energy gap and the visible finite-momentum splitting. A longitudinal field $B\\parallel c$ then acts as a linear amplifier of the hidden scale, opening two signed, field-linear readouts. The first is the compensation field $B^\\ast(\\mathbf Q)$, the position of minimum splitting, which is equal and opposite at the rotation-related partner momenta: a shift from zero field is itself evidence of a finite imbalance, its side gives the sign, and its magnitude, $|B^\\ast|\\simeq0.34$~T here, gives the scale. The second is the fixed-field contrast of the partner splittings, $\\simeq0.14$~meV at $1$~T, six times the zero-field excess: a sign check from just two spectra. Both readouts survive a $0.12$~meV energy resolution, and the construction carries over to any easy-axis collinear altermagnet, bringing $μ$eV altermagnetic exchange within present instrumental reach.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.26540",
  "author_total": 7,
  "authors": [
    {
      "name": "Guowen Jiang"
    },
    {
      "name": "Feilong Wang"
    },
    {
      "name": "Yunhua Wang"
    },
    {
      "name": "Fawei Zheng"
    },
    {
      "name": "Bin Xi"
    },
    {
      "name": "Hong-Gang Luo"
    },
    {
      "name": "Jize Zhao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0mh7w81r5fzwn.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.26540",
  "fulltext_url": null,
  "id": "0mh7w81r5fzwn",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.26540",
  "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",
      "cond-mat.str-el"
    ],
    [
      "openalex",
      "3104|Advanced Condensed Matter Physics"
    ]
  ],
  "openalex": "W7204523737",
  "pdf_url": "https://arxiv.org/pdf/2608.26540",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0mh7w81r5fzwn.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:22Z",
      "native_id": "2608.26540",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.26540"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Field-amplified readouts of weak altermagnetic exchange in MnF$_2$",
  "title_text": "Field-amplified readouts of weak altermagnetic exchange in MnF_2",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:22Z",
  "url": "https://research.draconitic.com/paper/0mh7w81r5fzwn",
  "venue": "arXiv",
  "versions": []
}