{
  "annotation_id": "5b357c70-fa04-40f5-90d9-6e5f43ca9c3d",
  "date_created": "2026-03-02T18:01:38.925000Z",
  "date_modified": "2026-03-02T18:01:38.925000Z",
  "file_hash": "970c836a1849d3a1a1675bb5ef17857866b96eeb8a2c2af0092979a326d69fc2",
  "private": false,
  "record": {
    "abstract": "We distinguish six classes of families of locally equivalent states in a\nstraightforward scheme for classifying all 2-q-bit states; four of the classes\nconsist of two subclasses each. The simple criteria that we stated recently for\nchecking a given state\u0027s positivity and separability are justified, and we\ndiscuss some important properties of Lewenstein-Sanpera decompositions. An\nupper bound is conjectured for the sum of the degree of separability of a\n2-q-bit state and its concurrence.",
    "arxiv_id": "quant-ph/0007053",
    "authors": [
      "Berthold-Georg Englert",
      "Nasser Metwally"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1007/s003400000502",
    "journal_ref": "Applied Physics B, vol. 72, 2001, pp. 35-42",
    "title": "Remarks on 2-q-bit states",
    "url": "https://arxiv.org/abs/quant-ph/0007053"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "f0864043-f57e-467e-bc3d-9925eaaff913",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}