{
  "annotation_id": "0ed3b175-9e9b-4b1b-bed4-9fbea7b8901b",
  "date_created": "2026-03-02T18:01:53.056000Z",
  "date_modified": "2026-03-02T18:01:53.056000Z",
  "file_hash": "f0ce1677bd934740d387c99b277b0b76a79cfcce5cb646a4ba6eae1c20f18470",
  "private": false,
  "record": {
    "abstract": "State estimation is a classical problem in quantum information. In\noptimization of estimation scheme, to find a lower bound to the error of the\nestimator is a very important step. So far, all the proposed tractable lower\nbounds use derivative of density matrix. However, sometimes, we are interested\nin quantities with singularity, e.g. concurrence etc. In the paper, lower\nbounds to a Mean Square Error (MSE) of an estimator are derived for a quantum\nestimation problem without smoothness assumptions. Our main idea is to replace\nthe derivative by difference, as is done in classical estimation theory. We\napplied the inequalities to several examples, and derived optimal estimator for\nsome of them.",
    "arxiv_id": "quant-ph/0207150",
    "authors": [
      "Yoshiyuki Tsuda",
      "Keiji Matsumoto"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Quantum estimation for non-differentiable models",
    "url": "https://arxiv.org/abs/quant-ph/0207150"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "52c20826-5a65-485f-bdd1-e346c0f4ab63",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}