{
  "abstract": "Identifying regimes in which interacting fermionic systems admit efficient classical simulation is a crucial task in quantum many-body physics. In this work, we rigorously establish the Gaussianity and classical simulability of sufficiently weakly interacting fermions. For the Gibbs state of a local interacting fermionic Hamiltonian $H=H_0+V$ at any finite temperature and in any spatial dimension, where $H_0$ is quadratic and $V$ is the interaction term, we show that there exists a positive interaction strength below which the Gibbs state is a convex mixture of fermionic Gaussian states. Moreover, based on this structure, we construct a polynomial-time classical sampler for the Gibbs state via Metropolis updates on a tree whose leaves are Gaussian states.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.35159",
  "author_total": 3,
  "authors": [
    {
      "name": "Zhengyi Han"
    },
    {
      "name": "Yuanchen Zhao"
    },
    {
      "name": "Zi-Wen Liu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fbn7gwcfzs4cw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.35159",
  "fulltext_url": null,
  "id": "fbn7gwcfzs4cw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.35159",
  "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",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Quantum many-body systems"
    ]
  ],
  "openalex": "W7214780810",
  "pdf_url": "https://arxiv.org/pdf/2609.35159",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fbn7gwcfzs4cw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:12Z",
      "native_id": "2609.35159",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.35159"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Weakly interacting fermionic Gibbs states are Gaussian mixtures and classically simulable",
  "title_text": "Weakly interacting fermionic Gibbs states are Gaussian mixtures and classically simulable",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:12Z",
  "url": "https://research.draconitic.com/paper/fbn7gwcfzs4cw",
  "venue": "arXiv",
  "versions": []
}