{
  "annotation_id": "4ac36c5e-811e-4f89-b817-7774b63d65cb",
  "date_created": "2026-03-02T18:02:24.072000Z",
  "date_modified": "2026-03-02T18:02:24.072000Z",
  "file_hash": "32df7ce4dbd48bc1cd0c279bc425dc6172d67c4a5338cfe522564ce857e3c95e",
  "private": false,
  "record": {
    "abstract": "This paper reconsiders the claimed rapidity of a scheme for the purification\nof the quantum state of a qubit, proposed recently in Jacobs 2003 Phys. Rev.\nA67 030301(R). The qubit starts in a completely mixed state, and information is\nobtained by a continuous measurement. Jacobs\u0027 rapid purification protocol uses\nHamiltonian feedback control to maximise the average purity of the qubit for a\ngiven time, with a factor of two increase in the purification rate over the\nno-feedback protocol. However, by re-examining the latter approach, we show\nthat it mininises the average time taken for a qubit to reach a given purity.\nIn fact, the average time taken for the no-feedback protocol beats that for\nJacobs\u0027 protocol by a factor of two. We discuss how this is compatible with\nJacobs\u0027 result, and the usefulness of the different approaches.",
    "arxiv_id": "quant-ph/0603062",
    "authors": [
      "H. M. Wiseman",
      "J. F. Ralph"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/1367-2630/8/6/090",
    "journal_ref": "New J. Phys. 8 (2006) 90",
    "title": "Reconsidering Rapid Qubit Purification by Feedback",
    "url": "https://arxiv.org/abs/quant-ph/0603062"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "a1c90d46-100b-462b-99ff-b7c0ef42f854",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}