{
  "annotation_id": "da86bef7-087b-4a57-85ed-2ca273d6eb1c",
  "date_created": "2026-03-02T18:02:23.626000Z",
  "date_modified": "2026-03-02T18:02:23.626000Z",
  "file_hash": "5987f3dfe4bfab9c27746c3557509b57b27c9181deeb29d1ae176613507c8eb3",
  "private": false,
  "record": {
    "abstract": "We show how to optimally unambiguously discriminate between two subspaces of\na Hilbert space. In particular we suppose that we are given a quantum system in\neither the state \\psi_{1}, where \\psi_{1} can be any state in the subspace\nS_{1}, or \\psi_{2}, where \\psi_{2} can be any state in the subspace S_{2}, and\nour task is to determine in which of the subspaces the state of our quantum\nsystem lies. We do not want to make a mistake, which means that our procedure\nwill sometimes fail if the subspaces are not orthogonal. This is a special case\nof the unambiguous discrimination of mixed states. We present the POVM that\nsolves this problem and several applications of this procedure, including the\ndiscrimination of multipartite states without classical communication.",
    "arxiv_id": "quant-ph/0602093",
    "authors": [
      "Janos A. Bergou",
      "Edgar Feldman",
      "Mark Hillery"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.73.032107",
    "journal_ref": "Phys. Rev. A 73, 032107 (2006)",
    "title": "Optimal unambiguous discrimination of two subspaces as a case in mixed   state discrimination",
    "url": "https://arxiv.org/abs/quant-ph/0602093"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "305a4e48-68d0-4d9f-a92a-a031ceef0c8e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}