{
  "annotation_id": "26e894bd-060b-4604-aabb-66106533e3ba",
  "date_created": "2026-03-02T18:01:41.719000Z",
  "date_modified": "2026-03-02T18:01:41.719000Z",
  "file_hash": "355928f866422d32ba8e477bbff1491c6d379de71ede5553fb731a251c5d8b80",
  "private": false,
  "record": {
    "abstract": "We calculate the trade-off between the quality of estimating the quantum\nstate of an ensemble of identically prepared qubits and the minimum level of\ndisturbance that has to be introduced by this procedure in quantum mechanics.\nThe trade-off is quantified using two mean fidelities: the operation fidelity\nwhich characterizes the average resemblance of the final qubit state to the\ninitial one, and the estimation fidelity describing the quality of the obtained\nestimate. We analyze properties of quantum operations saturating the\nachievability bound for the operation fidelity versus the estimation fidelity,\nwhich allows us to reduce substantially the complexity of the problem of\nfinding the trade-off curve. The reduced optimization problem has the form of\nan eigenvalue problem for a set of tridiagonal matrices, and it can be easily\nsolved using standard numerical tools.",
    "arxiv_id": "quant-ph/0104008",
    "authors": [
      "Konrad Banaszek",
      "Igor Devetak"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.64.052307",
    "journal_ref": "Phys. Rev. A 64, 052307 (2001)",
    "title": "Fidelity trade-off for finite ensembles of identically prepared qubits",
    "url": "https://arxiv.org/abs/quant-ph/0104008"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "0998334c-606b-48da-a3c6-8915e06bc82c",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}