{
  "annotation_id": "48d18fbf-5bf9-4992-8be8-c2d50f7629c3",
  "date_created": "2026-03-02T18:02:13.319000Z",
  "date_modified": "2026-03-02T18:02:13.319000Z",
  "file_hash": "495fab3102b134529b8f92a565ef5e9e2f7b7307b2c5959e32bc4cbc87ab2cda",
  "private": false,
  "record": {
    "abstract": "We analyze how an action of a qubit channel (map) can be estimated from the\nmeasured data that are incomplete or even inconsistent. That is, we consider\nsituations when measurement statistics is insufficient to determine consistent\nprobability distributions. As a consequence either the estimation\n(reconstruction) of the channel completely fails or it results in an unphysical\nchannel (i.e., the corresponding map is not completely positive). We present a\nregularization procedure that allows us to derive physically reasonable\nestimates (approximations) of quantum channels. We illustrate our procedure on\nspecific examples and we show that the procedure can be also used for a\nderivation of optimal approximations of operations that are forbidden by the\nlaws of quantum mechanics (e.g., the universal NOT gate).",
    "arxiv_id": "quant-ph/0412129",
    "authors": [
      "Mario Ziman",
      "Martin Plesch",
      "Vladimir Buzek"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1140/epjd/e2005-00020-2",
    "journal_ref": "The European Physical Journal D 32, Vol.10,215 - 222 (2005)",
    "title": "Process reconstruction from incomplete and/or inconsistent data",
    "url": "https://arxiv.org/abs/quant-ph/0412129"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "ef44c352-5e2b-4183-8559-3666f3bba467",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}