{
  "annotation_id": "143d98fb-f093-4bfd-9fa1-7360e1999f0b",
  "date_created": "2026-03-02T18:01:52.423000Z",
  "date_modified": "2026-03-02T18:01:52.423000Z",
  "file_hash": "15a4220f042b02221211094931b1a2313025bbf9a7fbcb258569649c3304cbd1",
  "private": false,
  "record": {
    "abstract": "We experimentally analyzed the statistical errors in quantum-state estimation\nand examined whether their lower bound, which is derived from the Cramer-Rao\ninequality, can be truly attained or not. In the experiments, polarization\nstates of bi-photons produced via spontaneous parametric down-conversion were\nestimated employing tomographic measurements. Using a new estimation strategy\nbased on Akaike\u0027s information criterion, we demonstrated that the errors\nactually approach the lower bound, while they fail to approach it using the\nconventional estimation strategy.",
    "arxiv_id": "quant-ph/0209074",
    "authors": [
      "Koji Usami",
      "Yoshihiro Nambu",
      "Yoshiyuki Tsuda",
      "Keiji Matsumoto",
      "Kazuo Nakamura"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.68.022314",
    "title": "A New Strategy of Quantum-State Estimation for Achieving the Cramer-Rao   Bound",
    "url": "https://arxiv.org/abs/quant-ph/0209074"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "748cdf78-0ac1-4f3b-b0a4-74a4022c0035",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}