{
  "annotation_id": "b4df5f86-9113-4e2f-9694-25fae8351d6b",
  "date_created": "2026-03-02T18:02:47.384000Z",
  "date_modified": "2026-03-02T18:02:47.384000Z",
  "file_hash": "f3bcc2298a7a44f435b7e11be07194031616800216d665e5e5e1b82be791a021",
  "private": false,
  "record": {
    "abstract": "Non-orthogonal bases of projectors on coherent states are introduced to\nexpand hermitean operators acting on the Hilbert space of a spin s. It is shown\nthat the expectation values of a hermitean operator A in a family of\n(2s+1)(2s+1) spin-coherent states determine the operator unambiguously. In\nother words, knowing the Q-symbol of A at (2s+1)(2s+1) points on the unit\nsphere is already sufficient in order to recover the operator. This provides a\nstraightforward method to reconstruct the mixed state of a spin since its\ndensity matrix is explicitly parametrized in terms of expectation values.\nFurthermore, a discrete P-symbol emerges naturally which is related to a basis\ndual to the original one.",
    "arxiv_id": "quant-ph/9906099",
    "authors": [
      "Jean-Pierre Amiet",
      "Stefan Weigert"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/1464-4266/2/2/309",
    "journal_ref": "J.Opt. B2 (2000) 118",
    "title": "Discrete Q- and P-symbols for spin s",
    "url": "https://arxiv.org/abs/quant-ph/9906099"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "61b7214e-acad-4239-816e-a02f0f0b21b7",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}