{
  "abstract": "Dissipative algorithms for preparing thermal and ground states typically require a total Hamiltonian simulation time that grows at least linearly with system size $N$, even when their mixing time grows only polylogarithmically. We achieve sublinear simulation time for free fermions by engineering local interactions with a bath whose size grows in proportion to the system size. Starting from arbitrary initial states, our thermal state preparation algorithm achieves trace-norm error $ε$ in total simulation time $\\widetilde{O}(\\sqrt{N}/ε)$ at fixed inverse temperature and bounded single-particle bandwidth, while ground state preparation of gapped systems requires only $\\mathrm{polylog}(N/ε)$ time. We further establish lower bounds for thermal state preparation within the bath protocols considered, identifying two obstacles to faster preparation, namely fourth-order deviations from the target thermal state and fluctuations induced by a random frequency shared by all bath qubits. Our results demonstrate that the linear simulation time barrier in dissipative state preparation can be overcome and clarify the bath and filter-design constraints that govern further complexity improvements.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.35370",
  "author_total": 3,
  "authors": [
    {
      "name": "Zhiyan Ding"
    },
    {
      "name": "Lin Lin"
    },
    {
      "name": "Ke Wang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/f73rerc51q7bq.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.35370",
  "fulltext_url": null,
  "id": "f73rerc51q7bq",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.35370",
  "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",
      "quant-ph"
    ],
    [
      "openalex",
      "1702|Quantum Computing Algorithms and Architecture"
    ]
  ],
  "openalex": "W7223947384",
  "pdf_url": "https://arxiv.org/pdf/2610.35370",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/f73rerc51q7bq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.35370",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.35370"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Sublinear thermal state and ground state preparation for free fermions via system-bath interaction",
  "title_text": "Sublinear thermal state and ground state preparation for free fermions via system-bath interaction",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/f73rerc51q7bq",
  "venue": "arXiv",
  "versions": []
}