{
  "annotation_id": "0035109a-a301-4214-b5eb-bcc207168467",
  "date_created": "2026-03-02T18:02:30.610000Z",
  "date_modified": "2026-03-02T18:02:30.610000Z",
  "file_hash": "162e2c726e7cafe4ad6d7154aeaf686291b68a4cf2b8868fa4aa473831435df9",
  "private": false,
  "record": {
    "abstract": "\"Nonfreeness\" is the (negative of the) difference between the von Neumann\nentropies of a given many-fermion state and the free state that has the same\n1-particle statistics. It also equals the relative entropy of the two states in\nquestion, i.e., it is the entropy of the given state relative to the\ncorresponding free state. The nonfreeness of a pure state is the same as its\n\"particle-hole symmetric correlation entropy\", a variant of an established\nmeasure of electron correlation. But nonfreeness is also defined for mixed\nstates, and this allows one to compare the nonfreeness of subsystems to the\nnonfreeness of the whole. Nonfreeness of a part does not exceed that in the\nwhole; nonfreeness is additive over independent subsystems; and nonfreeness is\nsuperadditive over subsystems that are independent on the 1-particle level.",
    "arxiv_id": "quant-ph/0608171",
    "authors": [
      "Alex D. Gottlieb",
      "Norbert J. Mauser"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Properties of nonfreeness: an entropy measure of electron correlation",
    "url": "https://arxiv.org/abs/quant-ph/0608171"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "da237791-03be-4c4a-b773-f93646976c87",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}