{
  "annotation_id": "a7d10e8f-d96d-40b8-a0ac-ba27ad997dd8",
  "date_created": "2026-03-02T18:01:59.482000Z",
  "date_modified": "2026-03-02T18:01:59.482000Z",
  "file_hash": "0dc7f5b04ac95933933aedca3773c9a7731e79c84b45d0a0cc031f5627714805",
  "private": false,
  "record": {
    "abstract": "In the King\u0027s Problem, a physicist is asked to prepare a d-state quantum\nsystem in any state of her choosing and give it to a king who measures one of\n(d+1) sets of mutually unbiased observables on it. The physicist is then\nallowed to make a control measurement on the system, following which the king\nreveals which set of observables he measured and challenges the physicist to\npredict correctly all the eigenvalues he found. This paper obtains an upper\nbound on the physicist\u0027s probability of success at this task if she is allowed\nto make measurements only on the system itself (the \"conventional\" solution)\nand not on the system as well as any ancillary systems it may have been coupled\nto in the preparation phase, as in the perfect solutions proposed recently. An\noptimal conventional solution, with a success probability of 0.7, is\nconstructed in d = 4; this is to be contrasted with the success probability of\n0.902 for the optimal conventional solution in d = 2. The gap between the best\nconventional solution and the perfect solution grows quite rapidly with\nincreasing d.",
    "arxiv_id": "quant-ph/0306119",
    "authors": [
      "P. K. Aravind"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1515/zna-2003-1204",
    "journal_ref": "Z. Naturforsch. 58a, 682-690 (2003)",
    "title": "Best conventional solutions to the King\u0027s Problem",
    "url": "https://arxiv.org/abs/quant-ph/0306119"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "0313558c-4c5b-4824-8bdd-48b763e95fa5",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}