{
  "annotation_id": "acb91e83-cd45-4c55-ab49-0b81ca55cf1d",
  "date_created": "2026-03-02T18:01:38.562000Z",
  "date_modified": "2026-03-02T18:01:38.562000Z",
  "file_hash": "01effe01f55b623a43a79b302052423e17111d1fe46592d279f1e266b30090e6",
  "private": false,
  "record": {
    "abstract": "Quantum states can be used to encode the information contained in a\ndirection, i.e., in a unit vector. We present the best encoding procedure when\nthe quantum state is made up of $N$ spins (qubits). We find that the quality of\nthis optimal procedure, which we quantify in terms of the fidelity, depends\nsolely on the dimension of the encoding space. We also investigate the use of\nspatial rotations on a quantum state, which provide a natural and less\ndemanding encoding. In this case we prove that the fidelity is directly related\nto the largest zeros of the Legendre and Jacobi polynomials. We also discuss\nour results in terms of the information gain.",
    "arxiv_id": "quant-ph/0006075",
    "authors": [
      "E. Bagan",
      "M. Baig",
      "A. Brey",
      "R. Munoz-Tapia",
      "R. Tarrach"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevLett.85.5230",
    "journal_ref": "Phys. Rev. Lett. 85, 5230 (2000)",
    "title": "Optimal strategies for sending information through a quantum channel",
    "url": "https://arxiv.org/abs/quant-ph/0006075"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "e1f22058-5d25-4c88-b55b-f50eafa10300",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}