{
  "annotation_id": "7a76387c-1316-4e6e-997b-19e371a423f2",
  "date_created": "2026-03-02T18:02:43.874000Z",
  "date_modified": "2026-03-02T18:02:43.874000Z",
  "file_hash": "dbc69cd32c859ea5262e15c72c6c093b376e8b707ed3950a32751fe296725ada",
  "private": false,
  "record": {
    "abstract": "Linden, Massar and Popescu have recently given an optimization argument to\nshow that a single two-qubit Werner state, or any other mixture of the\nmaximally entangled Bell states, cannot be purified by local operations and\nclassical communications. We generalise their result and give a simple\nexplanation. In particular, we show that no purification scheme using local\noperations and classical communications can produce a pure singlet from any\nmixed state of two spin-1/2 particles. More generally, no such scheme can\nproduce a maximally entangled state of any pair of finite-dimensional systems\nfrom a generic mixed state. We also show that the Werner states belong to a\nlarge class of states whose fidelity cannot be increased by such a scheme.",
    "arxiv_id": "quant-ph/9805088",
    "authors": [
      "Adrian Kent"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevLett.81.2839",
    "journal_ref": "Phys.Rev.Lett. 81 (1998) 2839-2841",
    "title": "Entangled Mixed States and Local Purification",
    "url": "https://arxiv.org/abs/quant-ph/9805088"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "9d95050e-afe6-493c-bfc4-e4b8ac95a49d",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}