{
  "annotation_id": "1921eb38-f3f9-4c91-b070-1e4fdee9741f",
  "date_created": "2026-03-02T18:02:34.440000Z",
  "date_modified": "2026-03-02T18:02:34.440000Z",
  "file_hash": "2fb5fade8f650868f1553cdb760fcab3aac1df2985409063c73316250aa8fa9f",
  "private": false,
  "record": {
    "abstract": "We address the estimation of the loss parameter of a bosonic channel probed\nby Gaussian signals. We derive the ultimate quantum bound on precision and show\nthat no improvement may be obtained by having access to the environment degrees\nof freedom. We found that, for small losses, the variance of the optimal\nestimator is proportional to the loss parameter itself, a result that\nrepresents a qualitative improvement over the shot noise limit. An observable\nbased on the symmetric logarithmic derivative is derived, which attains the\nultimate bound and may be implemented using Gaussian operations and photon\ncounting.",
    "arxiv_id": "quant-ph/0701216",
    "authors": [
      "Alex Monras",
      "Matteo G. A. Paris"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevLett.98.160401",
    "journal_ref": "Phys. Rev. Lett. 98, 160401 (2007)",
    "title": "Optimal quantum estimation of loss in bosonic channels",
    "url": "https://arxiv.org/abs/quant-ph/0701216"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "caaef524-8ddc-4107-bbf4-c00eb26576c3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}