{
  "annotation_id": "9089d67e-b7ed-4f98-8471-d850f40c4498",
  "date_created": "2026-03-02T18:02:47.940000Z",
  "date_modified": "2026-03-02T18:02:47.940000Z",
  "file_hash": "f78ade0a3e2d735bc804a93270a366649bcf435a148c2429a70763c6a2db95bb",
  "private": false,
  "record": {
    "abstract": "The need to retain the relative phases in quantum mechanics implies an\naddition law parametrized by a phase of two density operators required for the\npurification of a density matrix. This is shown with quantum tomography and the\nWigner function. Entanglement is determined in terms of phase dependent\nmultiplication.",
    "arxiv_id": "quant-ph/9910080",
    "authors": [
      "V. I. Man\u0027ko",
      "G. Marmo",
      "E. C. G. Sudarshan",
      "F. Zaccaria"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Purification of impure density operators and the recovery of   entanglements",
    "url": "https://arxiv.org/abs/quant-ph/9910080"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "d335dd9c-b4b4-4899-b662-919383e6c9f2",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}