{
  "abstract": "We report a systematic study of the superconducting ground state in the two-dimensional attractive Hubbard model, employing the {\\it numerically exact} auxiliary-field quantum Monte Carlo method. We focus primarily on the pairing order and condensate fraction across the BCS-BEC crossover. Our numerical calculations cover a broad and physically relevant parameter regime, with the interaction strength $U/t=2\\sim 12$ (where $t$ is the nearest-neighbor hopping amplitude) and fermion density $n=0.25\\sim 1.0$. We systematically characterize the dependence of the pairing order and condensate fraction on both the interaction strength and fermion density, and perform finite-size extrapolations to obtain their thermodynamic-limit values. As complementary quantities, we also provide high-precision numerical results for the double occupancy and total energy. Furthermore, we investigate the effects of next-nearest-neighbor hopping on the superconducting properties of the model. Our results offer a comprehensive set of unbiased numerical data for the attractive Hubbard model, establishing quantitative benchmarks for understanding superconductivity across the BCS-BEC crossover and for validating future theoretical and numerical approaches.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.06319",
  "author_total": 4,
  "authors": [
    {
      "name": "Hao Du"
    },
    {
      "name": "Qian Sun"
    },
    {
      "name": "Zhuotao Xie"
    },
    {
      "name": "Yuan-Yao He"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dp7eayf7sdr0j.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.06319",
  "fulltext_url": null,
  "id": "dp7eayf7sdr0j",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.06319",
  "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.str-el"
    ],
    [
      "openalex",
      "3107|Cold Atom Physics and Bose-Einstein Condensates"
    ]
  ],
  "openalex": "W7220678117",
  "pdf_url": "https://arxiv.org/pdf/2610.06319",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dp7eayf7sdr0j.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2610.06319",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.06319"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Pairing order and condensate fraction across the BCS-BEC crossover in the two-dimensional attractive Hubbard model",
  "title_text": "Pairing order and condensate fraction across the BCS-BEC crossover in the two-dimensional attractive Hubbard model",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/dp7eayf7sdr0j",
  "venue": "arXiv",
  "versions": []
}