{
  "abstract": "Motivated by recent experimental findings on UTe$_2$ via NMR and specific heat experiments, we theoretically explore the thermodynamic signatures of condensates with small superfluid density and characterize their physical properties. We identify the hidden superconducting phase $A_2$ composed of spin-up Cooper pairs at lower temperature ($T$) and field ($H$) under ambient pressure of UTe$_2$ and show that $A_2$ reappears at higher $H$ for all three principal field directions, $a$, $b$, and $c$-axis. The phase transition lines from the $A_1$ phase with spin down pairs to the $A_2$ phase in the $H$-$T$ plane are all horizontal in common, implying a universal physical origin due to the originating from the magnetic-energy gain of the spin-up pairing state with increasing magnetic field. This multiple-phase diagram is extended to these under pressure ($P$), resulting in a simple picture based on non-unitary spin-triplet pairing symmetry $^3B_{3u}$, which enables us to consistently capture the evolution of the superconducting phases throughout the entire $H$-$T$-$P$ phase space.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.19834",
  "author_total": 1,
  "authors": [
    {
      "name": "Kazushige Machida"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/enhkn0qgs0cvh.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.19834",
  "fulltext_url": null,
  "id": "enhkn0qgs0cvh",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.19834",
  "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.supr-con"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.19834",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-17",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/enhkn0qgs0cvh.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:19Z",
      "native_id": "2609.19834",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.19834"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.supr-con",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Generic thermodynamics of condensates with extremely small superfluid density ---Application to UTe$_2$ and hidden second phase transition---",
  "title_text": "Generic thermodynamics of condensates with extremely small superfluid density ---Application to UTe_2 and hidden second phase transition---",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:19Z",
  "url": "https://research.draconitic.com/paper/enhkn0qgs0cvh",
  "venue": "arXiv",
  "versions": []
}