{
  "annotation_id": "da9df8ad-8bbe-441e-bc8d-a3fa645fa79e",
  "date_created": "2026-03-02T18:02:44.969000Z",
  "date_modified": "2026-03-02T18:02:44.969000Z",
  "file_hash": "ec1aad553a3b4e31ac090256eb5e96e362a8132d92b58b5bcee6866a49679d18",
  "private": false,
  "record": {
    "abstract": "We study the problem of optimizing the Shannon mutual information for sources\nof real quantum states i.e. sources for which there is a basis in which all the\nstates have only real components. We consider in detail the sources ${\\cal\nE}_M$ of $M$ equiprobable qubit states lying symmetrically around the great\ncircle of real states on the Bloch sphere and give a variety of explicit\noptimal strategies. We also consider general real group-covariant sources for\nwhich the group acts irreducibly on the subset of all real states and prove the\nexistence of a real group-covariant optimal strategy, extending a theorem of\nDavies (E. B. Davies, IEEE. Inf. Theory {\\bf IT-24}, 596 (1978)). Finally we\npropose an optical scheme to implement our optimal strategies, enough simple to\nbe realized with present technology.",
    "arxiv_id": "quant-ph/9812062",
    "authors": [
      "Masahide Sasaki",
      "Stephen M. Barnett",
      "Richard Jozsa",
      "Masao Osaki",
      "Osamu Hirota"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.59.3325",
    "journal_ref": "Phys.Rev. A59 (2002) 3325",
    "title": "Accessible information and optimal strategies for real symmetrical   quantum sources",
    "url": "https://arxiv.org/abs/quant-ph/9812062"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "317a9125-6277-4fca-b528-858441e42e5b",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}