{
  "annotation_id": "45641b10-9205-4068-8e2d-f27a3fefc773",
  "date_created": "2026-03-02T18:02:16.429000Z",
  "date_modified": "2026-03-02T18:02:16.429000Z",
  "file_hash": "3599510bf8cd091c357202ef973128db28b7fb0e38051e6426236197927a4751",
  "private": false,
  "record": {
    "abstract": "The standard quantum search lacks a feature, enjoyed by many classical\nalgorithms, of having a fixed point, i.e. monotonic convergence towards the\nsolution. Recently a fixed point quantum search algorithm has been discovered,\nreferred to as the Phase-$\\pi/3$ search algorithm, which gets around this\nlimitation. While searching a database for a target state, this algorithm\nreduces the error probability from $\\epsilon$ to $\\epsilon^{2q+1}$ using $q$\noracle queries, which has since been proved to be asymptotically optimal. A\ndifferent algorithm is presented here, which has the same worst-case behavior\nas the Phase-$\\pi/3$ search algorithm but much better average-case behavior.\nFurthermore the new algorithm gives $\\epsilon^{2q+1}$ convergence for all\nintegral $q$, whereas the Phase-$\\pi/3$ search algorithm requires $q$ to be\n$(3^{n}-1)/2$ with $n$ a positive integer. In the new algorithm, the operations\nare controlled by two ancilla qubits, and fixed point behavior is achieved by\nirreversible measurement operations applied to these ancillas. It is an example\nof how measurement can allow us to bypass some restrictions imposed by\nunitarity on quantum computing.",
    "arxiv_id": "quant-ph/0505007",
    "authors": [
      "Tathagat Tulsi",
      "Lov Grover",
      "Apoorva Patel"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "A new algorithm for fixed point quantum search",
    "url": "https://arxiv.org/abs/quant-ph/0505007"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "b77e195c-dbc0-4a55-bccd-e30f28dfedde",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}