{
  "annotation_id": "72bb111b-c7a0-43f7-b384-eade4c001b47",
  "date_created": "2026-03-02T18:01:45.956000Z",
  "date_modified": "2026-03-02T18:01:45.956000Z",
  "file_hash": "dc10b5969692b9fad41d46d3e5eb034fb15b7edf160d25fdcb20bdeaefc152ba",
  "private": false,
  "record": {
    "abstract": "We consider the problem to single out a particular state among $2^n$\northogonal pure states. As it turns out, in general the optimal strategy is not\nto measure the particles separately, but to consider joint properties of the\n$n$-particle system. The required number of propositions is $n$. There exist\n$2^n!$ equivalent operational procedures to do so. We enumerate some\nconfigurations for three particles, in particular the\nGreenberger-Horne-Zeilinger (GHZ)- and W-states, which are specific cases of a\nunitary transformation For the GHZ-case, an explicit physical meaning of the\nprojection operators is discussed.",
    "arxiv_id": "quant-ph/0105046",
    "authors": [
      "Niko Donath",
      "Karl Svozil"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.65.044302",
    "journal_ref": "Physical Review A 66, 044302 (2002)",
    "title": "Finding a state in a haystack",
    "url": "https://arxiv.org/abs/quant-ph/0105046"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "2fdb5b4a-bbae-40d3-b5d6-ed41fa07541c",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}