{
  "annotation_id": "e658e09f-05ce-4174-af05-552e8d8f91f3",
  "date_created": "2026-03-02T18:02:16.223000Z",
  "date_modified": "2026-03-02T18:02:16.223000Z",
  "file_hash": "6c3faef70925d636a0bcbe9e716c0e41d6504fe12241b5e8b8fb3583d7fee69e",
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  "record": {
    "abstract": "It has been claimed in the literature that impossibility of faster-than-light\nquantum communication has an origin of indistinguishability of ensembles with\nthe same density matrix. We show that the two concepts are not related. We\nargue that: 1) even with an ideal single-atom-precision measurement, it is\ngenerally impossible to produce two ensembles with exactly the same density\nmatrix; or 2) to produce ensembles with the same density matrix, classical\ncommunication is necessary. Hence the impossibility of faster-than-light\ncommunication does not imply the indistinguishability of ensembles with the\nsame density matrix.",
    "arxiv_id": "quant-ph/0506047",
    "authors": [
      "Chuan Wang",
      "Gui Lu Long",
      "Yang Sun"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/6102/44/4/622",
    "journal_ref": "Commun. Theor. Phys. (Beijing, China) 44 (2005) pp. 622-624",
    "title": "No-relationship between impossibility of faster-than-light quantum   communication and distinction of ensembles with the same density matrix",
    "url": "https://arxiv.org/abs/quant-ph/0506047"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "5a4c8047-fc50-4e44-a552-a0c5f60e4d35",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}