{
  "annotation_id": "05d569e0-d984-428f-9f16-6687a5891b4a",
  "date_created": "2026-03-02T18:02:13.029000Z",
  "date_modified": "2026-03-02T18:02:13.029000Z",
  "file_hash": "76043f2f12da3288e87a9061244f64282da8e2f01aa84be6289790f476bf0aad",
  "private": false,
  "record": {
    "abstract": "A general quantum measurement on an unknown quantum state enables us to\nestimate what the state originally was. Simultaneously, the measurement has a\ndestructive effect on a measured quantum state which is reflected by the\ndecrease of the output fidelity. We show for any $d$-level system that quantum\nnon-demolition (QND) measurement controlled by a suitably prepared ancilla is a\nmeasurement in which the decrease of the output fidelity is minimal. The ratio\nbetween the estimation fidelity and the output fidelity can be continuously\ncontrolled by the preparation of the ancilla. Different measurement strategies\non the ancilla are also discussed. Finally, we propose a feasible scheme of\nsuch a measurement for atomic and optical 2-level systems based on basic\ncontrolled-NOT gate.",
    "arxiv_id": "quant-ph/0501031",
    "authors": [
      "Ladislav Mi\u0161ta Jr.",
      "Radim Filip"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.72.034307",
    "title": "Quantum non-demolition measurement saturates fidelity trade-off",
    "url": "https://arxiv.org/abs/quant-ph/0501031"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "fdfca0e4-b337-4064-8d2f-7c1b8bbfb4cd",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}