{
  "annotation_id": "a2cd1848-9d39-4e02-9c36-704c664484f0",
  "date_created": "2026-03-02T18:01:39.348000Z",
  "date_modified": "2026-03-02T18:01:39.348000Z",
  "file_hash": "acd2f57796d5cb968e0e4537d3f799c39e23f8799328ca45c9a17980ad4c2a82",
  "private": false,
  "record": {
    "abstract": "We analyze various scenarios for entangling two initially unentangled qubits.\nIn particular, we propose an optimal universal entangler which entangles a\nqubit in unknown state $|\\Psi\u003e$ with a qubit in a reference (known) state\n$|0\u003e$. That is, our entangler generates the output state which is as close as\npossible to the pure (symmetrized) state $(|\\Psi\u003e|0\u003e +|0\u003e|\\Psi\u003e)$. The most\nattractive feature of this entangling machine, is that the fidelity of its\nperformance (i.e. the distance between the output and the ideally entangled --\nsymmetrized state) does not depend on the input and takes the constant value\n$F= (9+3\\sqrt{2})/14\\simeq 0.946$. We also analyze how to optimally generate\nfrom a single qubit initially prepared in an unknown state $|\\Psi\\r$ a two\nqubit entangled system which is as close as possible to a Bell state\n$(|\\Psi\\r|\\Psi^\\perp\\r+|\\Psi^\\perp\\r|\\Psi\\r)$, where $\\l\\Psi|\\Psi^\\perp\\r =0$.",
    "arxiv_id": "quant-ph/0006045",
    "authors": [
      "Vladimir Buzek",
      "Mark Hillery"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.62.022303",
    "journal_ref": "Phys. Rev. A 62 (2000) 022303",
    "title": "Optimal manipulations with qubits: Universal quantum entanglers",
    "url": "https://arxiv.org/abs/quant-ph/0006045"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "f9ebdff6-3fe3-48e5-84a7-abafd2aa03be",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}