{
  "abstract": "The interplay between polar and altermagnetic orders remains largely unexplored in the broader landscape of correlated electron systems. Density functional theory (DFT) within the PBEsol + $U$ treatment propose Ca$_{3}$Ru$_{2}$O$_{7}$ as a polar altermagnet, reliant on the transformation of the experimentally reported $Bb2_{1}m$ phase to a lower symmetry $Pn2_{1}a$ structure. Here, we perform a targeted search for the $Pn2_{1}a$ phase using synchrotron X-ray diffraction on single crystals of Ca$_{3}$Ru$_{2}$O$_{7}$ and Ca$_{3}$(Ru$_{0.99}$Ti$_{0.01}$)$_{2}$O$_{7}$. No diffraction signature of the $Pn2_{1}a$ structure is detected down to 20 K within experimental limits. Through diffraction simulations, we translate this result into a quantitative upper bound on the symmetry breaking distortion amplitude, which we find to be significantly smaller than the DFT predicted distortion. Our DFT calculations further motivate dilute Ti substitution ($\\lesssim 2\\%$) as an alternative route to stabilize the low symmetry phase, for which we again find no clear evidence for this putative $Pn2_{1}a$ structure that hosts altermagnetism. Our findings indicate that PBEsol + $U$ over-stabilizes a $Pn2_{1}a$ distortion, and the measured bounds provide benchmark for future calculations. Ti substitution exceeding $\\sim$3% reveals a chemically tunable polar altermagnetic phase within the $Bb2_{1}m$ structure and we theoretically demonstrate that the spin-splitting can be tuned by Ti substitution. By combining DFT, diffraction simulations and synchrotron X-ray measurements, our study demonstrates a general methodology to quantify subtle structural distortions that underlie emergent electronic and magnetic phases.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.16181",
  "author_total": 18,
  "authors": [
    {
      "name": "Akash Saha"
    },
    {
      "name": "Yihuang Xiong"
    },
    {
      "name": "Vladimir A. Stoica"
    },
    {
      "name": "Subin Mali"
    },
    {
      "name": "Aaron Pearre"
    },
    {
      "name": "Saugata Sarker"
    },
    {
      "name": "Huaiyu Wang"
    },
    {
      "name": "Yufei Zhao"
    },
    {
      "name": "Evguenia Karapetrova"
    },
    {
      "name": "Yu Wang"
    },
    {
      "name": "Jadupati Nag"
    },
    {
      "name": "Zachary W. Hazenstab"
    },
    {
      "name": "Seng Huat Lee"
    },
    {
      "name": "Long-Qing Chen"
    },
    {
      "name": "Geoffroy Hautier"
    },
    {
      "name": "Binghai Yan"
    },
    {
      "name": "Zhiqiang Mao"
    },
    {
      "name": "Venkatraman Gopalan"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4s6pj9zyn9c7q.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.16181",
  "fulltext_url": null,
  "id": "4s6pj9zyn9c7q",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.16181",
  "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.mtrl-sci"
    ],
    [
      "arxiv",
      "cond-mat.str-el"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2606.16181",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4s6pj9zyn9c7q.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2606.16181",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.16181"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Evaluating the Structural Basis for Polar Altermagnet Candidate Ca$_{3}$(Ru,Ti)$_{2}$O$_{7}$",
  "title_text": "Evaluating the Structural Basis for Polar Altermagnet Candidate Ca_3(Ru,Ti)_2O_7",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/4s6pj9zyn9c7q",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1103/nb59-vxyy",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}