{
  "annotation_id": "09c6d227-5430-4b5b-8592-5c9c8f0e01d3",
  "date_created": "2026-03-02T18:02:24.197000Z",
  "date_modified": "2026-03-02T18:02:24.197000Z",
  "file_hash": "555c349c2ac370ab83e88679d87eb162005f1d7a4c41ac04213653c45b53f1b7",
  "private": false,
  "record": {
    "abstract": "We consider quantum ensembles which are determined by pre- and\npost-selection. Unlike the case of only pre-selected ensembles, we show that in\nthis case the probabilities for measurement outcomes at intermediate times\nsatisfy causality only rarely; such ensembles can in general be used to signal\nbetween causally disconnected regions. We show that under restrictive\nconditions, there are certain non-trivial bi-partite ensembles which do satisfy\ncausality. These ensembles give rise to a violation of the CHSH inequality,\nwhich exceeds the maximal quantum violation given by Tsirelson\u0027s bound, $B_{\\rm\nCHSH}\\le 2\\sqrt2$, and obtains the Popescu-Rohrlich bound for the maximal\nviolation, $B_{\\rm CHSH}\\le 4$. This may be regarded as an a posteriori\nrealization of super-correlations, which have recently been termed\nPopescu-Rohrlich boxes.",
    "arxiv_id": "quant-ph/0601122",
    "authors": [
      "S. Marcovitch",
      "B. Reznik",
      "L. Vaidman"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.75.022102",
    "journal_ref": "Phys. Rev. A 75, 022102 (2007)",
    "title": "Quantum Mechanical Realization of a Popescu-Rohrlich Box",
    "url": "https://arxiv.org/abs/quant-ph/0601122"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "f51962d2-40bc-466c-962a-3d3576b3d39e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}