{
  "abstract": "The search for candidate Kitaev materials has largely focused on 4$d$ and 5$d$ transition-metal compounds with various lattice geometries. In contrast, investigations of rare-earth 4$f$ systems have thus far been restricted mainly to honeycomb and triangular lattices. In this work, we investigate the rare-earth-based double perovskites Ba$_2$YbNbO$_6$ and Ba$_2$NdNbO$_6$, which crystallize in a face-centered cubic structure. Magnetization and heat-capacity measurements establish isolated ${j_{\\rm eff}} = 1/2$ Kramers doublet ground states arising from strong spin-orbit coupling (SOC) and crystal electric-field effects, which are further supported by density-functional theory calculations. Millikelvin-temperature thermodynamic measurements reveal long-range magnetic order with moderate frustration in both compounds. The emergence of magnetic order may be understood within an order-by-disorder scenario, as theoretically proposed for rare-earth fcc lattices with finite Kitaev interactions. Our results thus identify Ba$_2$YbNbO$_6$ and Ba$_2$NdNbO$_6$ as promising rare-earth spin-orbit-entangled magnets and motivate further experimental and theoretical investigations aimed at determining the complete exchange tensor to elucidate the microscopic origin of the underlying magnetic interactions.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Physcal Review B 114, 144403 (2016)",
  "arxiv": "2608.01022",
  "author_total": 10,
  "authors": [
    {
      "name": "S. M. Hossain"
    },
    {
      "name": "Sk. Soyeb Ali"
    },
    {
      "name": "S. Mohanty"
    },
    {
      "name": "R. Kolay"
    },
    {
      "name": "M. P. Saravanan"
    },
    {
      "name": "A. K. Yogi"
    },
    {
      "name": "Y. Tokiwa"
    },
    {
      "name": "R. Nath"
    },
    {
      "name": "S. K. Panda"
    },
    {
      "name": "M. Majumder"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0mckk55q11py6.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.01022",
  "fulltext_url": null,
  "id": "0mckk55q11py6",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.01022",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2608.01022",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0mckk55q11py6.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:14Z",
      "native_id": "2608.01022",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.01022"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Spin-orbit-entangled frustrated magnetism in fcc Ba$_2$(Yb,Nd)NbO$_6$ double perovskites",
  "title_text": "Spin-orbit-entangled frustrated magnetism in fcc Ba_2(Yb,Nd)NbO_6 double perovskites",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:14Z",
  "url": "https://research.draconitic.com/paper/0mckk55q11py6",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1103/lfzt-f261",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}