{
  "annotation_id": "204bbc9d-aa35-42bc-800f-98bf6a3624a8",
  "date_created": "2026-03-02T18:01:49.388000Z",
  "date_modified": "2026-03-02T18:01:49.388000Z",
  "file_hash": "ed2cf07e186fa30098a390c9e890d4c62c3b12818027af9f57ebfaf5aace8c6c",
  "private": false,
  "record": {
    "abstract": "We investigate the extent to which we can establish whether or not two\nquantum systems have been prepared in the same state. We investigate the\npossibility of universal unambiguous state comparison. We show that it is\nimpossible to conclusively identify two pure unknown states as being identical,\nand construct the optimal measurement for conclusively identifying them as\nbeing different. We then derive optimal strategies for state comparison when\nthe state of each system is one of two known states.",
    "arxiv_id": "quant-ph/0202087",
    "authors": [
      "Stephen M. Barnett",
      "Anthony Chefles",
      "Igor Jex"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1016/S0375-9601(02)01602-X",
    "title": "Comparison of two unknown pure quantum states",
    "url": "https://arxiv.org/abs/quant-ph/0202087"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "c318cab1-7fa8-4572-8ac3-e61a8a8bbe1d",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}