{
  "annotation_id": "4a27695f-2d70-41d4-8bff-e90a8039b518",
  "date_created": "2026-03-02T18:01:42.419000Z",
  "date_modified": "2026-03-02T18:01:42.419000Z",
  "file_hash": "3a1757a61a92f5332f7cf93c56ebb39f8f80d7f0b48ee8da52bd0c6609b705af",
  "private": false,
  "record": {
    "abstract": "We construct the optimal strategy for the estimation of an unknown unitary\ntransformation $U\\in SU(d)$. This includes, in addition to a convenient\nmeasurement on a probe system, finding which is the best initial state on which\n$U$ is to act. When $U\\in SU(2)$, such an optimal strategy can be applied to\nestimate simultaneously both the direction and the strength of a magnetic\nfield, and shows how to use a spin 1/2 particle to transmit information about a\nwhole coordinate system instead of only a direction in space.",
    "arxiv_id": "quant-ph/0012015",
    "authors": [
      "A. Acin",
      "E. Jane",
      "G. Vidal"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.64.050302",
    "journal_ref": "Phys. Rev. A 64, 050302(R) (2001).",
    "title": "Optimal estimation of quantum dynamics",
    "url": "https://arxiv.org/abs/quant-ph/0012015"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "c57582a1-eede-4fc5-a834-a05b0d117374",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}