{
  "annotation_id": "2517c597-3e38-479e-8a9e-908612f5b59c",
  "date_created": "2026-03-02T18:02:27.710000Z",
  "date_modified": "2026-03-02T18:02:27.710000Z",
  "file_hash": "ecc2fdaba7606cf737a9daa9f4eddbac6e70467c2420c6611010e164014eb0f8",
  "private": false,
  "record": {
    "abstract": "We compute the fidelity between the ground states of general quadratic\nfermionic hamiltonians and analyze its connections with quantum phase\ntransitions. Each of these systems is characterized by a $L\\times L$ real\nmatrix whose polar decomposition, into a non-negative $\\Lambda$ and a unitary\n$T$, contains all the relevant ground state (GS) information. The boundaries\nbetween different regions in the GS phase diagram are given by the points of,\npossibly asymptotic, singularity of $\\Lambda$. This latter in turn implies a\ncritical drop of the fidelity function. We present general results as well as\ntheir exemplification by a model of fermions on a totally connected graph.",
    "arxiv_id": "quant-ph/0606130",
    "authors": [
      "P. Zanardi",
      "M. Cozzini",
      "P. Giorda"
    ],
    "categories": [
      "quant-ph",
      "cond-mat.str-el"
    ],
    "doi": "10.1088/1742-5468/2007/02/L02002",
    "title": "Ground state fidelity and quantum phase transitions in free Fermi   systems",
    "url": "https://arxiv.org/abs/quant-ph/0606130"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "59f143e6-aa88-4225-bd2f-e34471ad38fe",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}