{
  "annotation_id": "8a35568e-2ba3-4ccf-a76f-ebe15b2b4a2e",
  "date_created": "2026-03-02T18:02:10.422000Z",
  "date_modified": "2026-03-02T18:02:10.422000Z",
  "file_hash": "e1107e9cecfd829d09da1e5d78e3c85bc8842df83bc27d3cd7cdf590b85aad2e",
  "private": false,
  "record": {
    "abstract": "We show that differently constructed ensembles having the same density matrix\nmay be physically distinguished by observing fluctuations of some observables.\nAn explicit expression for fluctuations of an observable in an ensemble is\ngiven. This result challenges Peres\u0027s fundamental postulate and seems to be\ncontrary to the widely-spread belief that ensembles with the same density\nmatrix are physically identical. This leads us to suggest that the current\nliquid NMR quantum computing is truly quantum-mechanical in nature.",
    "arxiv_id": "quant-ph/0408079",
    "authors": [
      "Gui-Lu Long",
      "Yi-Fan Zhou",
      "Jia-Qi Jin",
      "Yang Sun"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Distinctness of ensembles having the same density matrix and the nature   of liquid NMR quantum computing",
    "url": "https://arxiv.org/abs/quant-ph/0408079"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "3ac1deca-9c83-4235-a6ea-00ab160bfc9e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}