{
  "abstract": "We study the spin-1/2 nearest-neighbor Heisenberg model on the breathing pyrochlore lattice in the mixed ferro-antiferromagnetic regime, where one tetrahedral sublattice is antiferromagnetic and the other ferromagnetic. The classical ground-state manifold is then that of the nearest-neighbor face-centered-cubic (fcc) antiferromagnet built from composite tetrahedral moments. Classical Monte Carlo simulations and the self-consistent Gaussian approximation show that thermal order-by-disorder lifts its subextensive degeneracy and selects the collinear Type-I state with wave vector $X=(1,0,0)$ through a strongly first-order transition. Pseudofermion functional renormalization group calculations for $S=1/2$ and $S=1$ reveal a nonmagnetic window adjacent to the decoupled antiferromagnetic-tetrahedron limit, beyond which $X$ order reappears. Density matrix renormalization group calculations show that this window is not featureless: the antiferromagnetic tetrahedra develop nearly ideal tetramer correlations, with four bonds carrying $\\langle\\mathbf{S}_i\\cdot\\mathbf{S}_j\\rangle\\simeq-1/2$ and the two opposite bonds $\\simeq+1/4$, while the structure factor retains broad maxima at $X$. A third-order effective Hamiltonian in the tetrahedral-singlet manifold explains this: reversing the sign of the inter-tetrahedron coupling converts Tsunetsugu's dimer selection into a uniform tetramer selection, as confirmed by exact diagonalization. A dynamic high-temperature expansion traces how local tetrahedral excitations give way to low-energy $X$-centered spectral weight. Finally, we place density-functional parameters for eight structures of spin-3/2 breathing chromium thiospinels in the classical phase diagram. The mapping reproduces the $\\mathbf{k}=(1,0,0)$ order of CuInCr$_4$S$_8$, accounts for the absence of order in LiGaCr$_4$S$_8$, and predicts Type-I order for LiInCr$_4$S$_8$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.30162",
  "author_total": 11,
  "authors": [
    {
      "name": "Sourin Chatterjee"
    },
    {
      "name": "Kelvin Salou-Smith"
    },
    {
      "name": "Benedikt Schneider"
    },
    {
      "name": "Imre Hagymási"
    },
    {
      "name": "Arnaud Ralko"
    },
    {
      "name": "Johannes Reuther"
    },
    {
      "name": "Jeffrey G. Rau"
    },
    {
      "name": "Karlo Penc"
    },
    {
      "name": "Harald O. Jeschke"
    },
    {
      "name": "Ludovic D. C. Jaubert"
    },
    {
      "name": "Yasir Iqbal"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/crfta829se8va.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.30162",
  "fulltext_url": null,
  "id": "crfta829se8va",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.30162",
  "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.mtrl-sci"
    ],
    [
      "arxiv",
      "cond-mat.str-el"
    ],
    [
      "openalex",
      "3104|Advanced Condensed Matter Physics"
    ]
  ],
  "openalex": "W7214402672",
  "pdf_url": "https://arxiv.org/pdf/2609.30162",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/crfta829se8va.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:24:11Z",
      "native_id": "2609.30162",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.30162"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "From dimensional reduction to tetramerization in mixed ferro-antiferro breathing pyrochlores",
  "title_text": "From dimensional reduction to tetramerization in mixed ferro-antiferro breathing pyrochlores",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:11Z",
  "url": "https://research.draconitic.com/paper/crfta829se8va",
  "venue": "arXiv",
  "versions": []
}