{
  "abstract": "A central goal of modern condensed matter physics is to uncover new quantum states of matter arising from the intertwined effects of strong electron correlations, magnetism, and band topology. Heavy-fermion phases, generated by Kondo interactions, represent one of the most remarkable manifestations of electronic correlations, and topological heavy-fermion states have been identified in several non-magnetic materials. Yet, the consequences of their competition with magnetic order have remained largely unexplored. Here, we reveal a new phenomenon: the spontaneous spatial separation of correlated quantum phases. By showing that magnetism can drive distinct strongly correlated electronic states to coexist in different regions of a single material, our work establishes a previously unknown mechanism for organizing quantum matter and opens a new direction in the study of correlated topological systems. Using \\emph{bulk-sensitive} probes, we show that UAsS crystals are, in the bulk, metallic ferromagnets with only moderate correlation-driven band renormalizations. First-principles calculations reveal a topological electronic structure hosting both nodal lines and Weyl points, pointing to a rich underlying topology. Angle-resolved photoemission spectroscopy (ARPES) measurements are consistent with these predictions, resolving the nodal lines and Weyl crossings. In striking contrast, \\emph{surface-sensitive} ARPES and scanning tunneling microscopy/spectroscopy (STM/STS) measurements reveal a pronounced flat band pinned at the Fermi level, accompanied by a sharp resonance -- hallmarks of an emergent, strongly correlated Kondo state not captured by first-principles calculations.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.20432",
  "author_total": 31,
  "authors": [
    {
      "name": "Nazar Zaremba"
    },
    {
      "name": "Susmita Changdar"
    },
    {
      "name": "Haojie Guo"
    },
    {
      "name": "Iñigo Robredo"
    },
    {
      "name": "Daniel Lozano-Gomez"
    },
    {
      "name": "Andreas Leithe-Jasper"
    },
    {
      "name": "Rui Lou"
    },
    {
      "name": "Yurii Prots"
    },
    {
      "name": "Mitja Krnel"
    },
    {
      "name": "Markus König"
    },
    {
      "name": "Konstantin Semeniuk"
    },
    {
      "name": "Berit H. Goodge"
    },
    {
      "name": "Yuri Grin"
    },
    {
      "name": "Andrii Kuibarov"
    },
    {
      "name": "Oleksandr Suvorov"
    },
    {
      "name": "Alexander Fedorov"
    },
    {
      "name": "Adam Pikul"
    },
    {
      "name": "Ivan Soldatov"
    },
    {
      "name": "Rudolf Schäfer"
    },
    {
      "name": "Bernd Büchner"
    },
    {
      "name": "Oksana Kvitnitskaya"
    },
    {
      "name": "Yurii Naidyuk"
    },
    {
      "name": "Louis Lamm"
    },
    {
      "name": "Meike Pfeiffer"
    },
    {
      "name": "Elena Hassinger"
    },
    {
      "name": "Matthias Vojta"
    },
    {
      "name": "Sergey Borisenko"
    },
    {
      "name": "Miguel M. Ugeda"
    },
    {
      "name": "Jeroen van den Brink"
    },
    {
      "name": "Eteri Svanidze"
    },
    {
      "name": "Maia G. Vergniory"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/57w2c6rww07d1.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.20432",
  "fulltext_url": null,
  "id": "57w2c6rww07d1",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.20432",
  "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.str-el"
    ],
    [
      "openalex",
      "3104|Rare-earth and actinide compounds"
    ]
  ],
  "openalex": "W7213609284",
  "pdf_url": "https://arxiv.org/pdf/2609.20432",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-17",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/57w2c6rww07d1.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:19Z",
      "native_id": "2609.20432",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.20432"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Emergent Surface Kondo Flat Band Driven by Competing Interactions in a Topological Ferromagnet",
  "title_text": "Emergent Surface Kondo Flat Band Driven by Competing Interactions in a Topological Ferromagnet",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:19Z",
  "url": "https://research.draconitic.com/paper/57w2c6rww07d1",
  "venue": "arXiv",
  "versions": []
}