{
  "annotation_id": "2f2a3aa3-0a7f-49a0-8306-2bd550abd59f",
  "date_created": "2026-03-02T18:02:27.217000Z",
  "date_modified": "2026-03-02T18:02:27.217000Z",
  "file_hash": "3034cabd2e1ddcc500163a4346cd0c689d33b4b08649107e1f791c85175da0c0",
  "private": false,
  "record": {
    "abstract": "The structure of all completely positive quantum operations is investigated\nwhich transform pure two-qubit input states of a given degree of entanglement\nin a covariant way. Special cases thereof are quantum NOT operations which\ntransform entangled pure two-qubit input states of a given degree of\nentanglement into orthogonal states in an optimal way. Based on our general\nanalysis all covariant optimal two-qubit quantum NOT operations are determined.\nIn particular, it is demonstrated that only in the case of maximally entangled\ninput states these quantum NOT operations can be performed perfectly.",
    "arxiv_id": "quant-ph/0603184",
    "authors": [
      "J. Novotny",
      "G. Alber",
      "I. Jex"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.73.062311",
    "title": "Completely positive covariant two-qubit quantum processes and optimal   quantum NOT operations for entangled qubit pairs",
    "url": "https://arxiv.org/abs/quant-ph/0603184"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "f6b63598-dd5b-48d9-923d-824d7bd3532d",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}