{
  "annotation_id": "2f76de33-d71c-4f76-8fc7-9555a87d36a6",
  "date_created": "2026-03-02T18:01:56.501000Z",
  "date_modified": "2026-03-02T18:01:56.501000Z",
  "file_hash": "5924d2548bb3acc54b940557036ceb609352d7c5a222ef2e9707b5b431b8d504",
  "private": false,
  "record": {
    "abstract": "Relativistic effects affect nearly all notions of quantum information theory.\nThe vacuum behaves as a noisy channel, even if the detectors are perfect. The\nstandard definition of a reduced density matrix fails for photon polarization\nbecause the transversality condition behaves like a superselection rule. We can\nhowever define an effective reduced density matrix which corresponds to a\nrestricted class of positive operator-valued measures. There are no pure photon\nqubits, and no exactly orthogonal qubit states. Reduced density matrices for\nthe spin of massive particles are well-defined, but are not covariant under\nLorentz transformations. The spin entropy is not a relativistic scalar and has\nno invariant meaning. The distinguishability of quantum signals and their\nentanglement depend on the relative motion of observers.",
    "arxiv_id": "quant-ph/0301065",
    "authors": [
      "Asher Peres",
      "Daniel R. Terno"
    ],
    "categories": [
      "quant-ph"
    ],
    "journal_ref": "Int. J. Quant. Info. 1, 225 (2003)",
    "title": "Quantum information and special relativity",
    "url": "https://arxiv.org/abs/quant-ph/0301065"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "c28a8957-36c3-4606-99d1-80df70849eb4",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}