{
  "annotation_id": "9c2832bd-0104-4112-895f-5e4253621645",
  "date_created": "2026-03-02T18:02:33.711000Z",
  "date_modified": "2026-03-02T18:02:33.711000Z",
  "file_hash": "df6c959960d43813c939743f53e90932a5c5ba6ae3dfd7c950679e1dd490f719",
  "private": false,
  "record": {
    "abstract": "We address the problem of unambiguous discrimination among oracle operators.\nThe general theory of unambiguous discrimination among unitary operators is\nextended with this application in mind. We prove that entanglement with an\nancilla cannot assist any discrimination strategy for commuting unitary\noperators. We also obtain a simple, practical test for the unambiguous\ndistinguishability of an arbitrary set of unitary operators on a given system.\nUsing this result, we prove that the unambiguous distinguishability criterion\nis the same for both standard and minimal oracle operators. We then show that,\nexcept in certain trivial cases, unambiguous discrimination among all standard\noracle operators corresponding to integer functions with fixed domain and range\nis impossible. However, we find that it is possible to unambiguously\ndiscriminate among the Grover oracle operators corresponding to an arbitrarily\nlarge unsorted database. The unambiguous distinguishability of standard oracle\noperators corresponding to totally indistinguishable functions, which possess a\nstrong form of classical indistinguishability, is analysed. We prove that these\noperators are not unambiguously distinguishable for any finite set of totally\nindistinguishable functions on a Boolean domain and with arbitrary fixed range.\nSets of such functions on a larger domain can have unambiguously\ndistinguishable standard oracle operators and we provide a complete analysis of\nthe simplest case, that of four functions. We also examine the possibility of\nunambiguous oracle operator discrimination with multiple parallel calls and\ninvestigate an intriguing unitary superoperator transformation between standard\nand entanglement-assisted minimal oracle operators.",
    "arxiv_id": "quant-ph/0702245",
    "authors": [
      "Anthony Chefles",
      "Akira Kitagawa",
      "Masahiro Takeoka",
      "Masahide Sasaki",
      "Jason Twamley"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/1751-8113/40/33/016",
    "title": "Unambiguous discrimination among oracle operators",
    "url": "https://arxiv.org/abs/quant-ph/0702245"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "81c4750a-3686-4ac2-899f-864769ec93d6",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}