{
  "annotation_id": "f680b870-77f7-4123-b18b-7fb31c39e564",
  "date_created": "2026-03-02T18:02:34.107000Z",
  "date_modified": "2026-03-02T18:02:34.107000Z",
  "file_hash": "a95f23475c7b9f8162247ff130bc39feaab8d8647ba4c8425218e5c4c47181ef",
  "private": false,
  "record": {
    "abstract": "We witness experimentally the presence of macroscopic coherence in Gaussian\nquantum states using a recently proposed criterion (E.G. Cavalcanti and M.\nReid, Phys. Rev. Lett. 97, 170405 (2006)). The macroscopic coherence stems from\ninterference between macroscopically distinct states in phase space and we\nprove experimentally that even the vacuum state contains these features with a\ndistance in phase space of $0.51\\pm0.02$ shot noise units (SNU). For squeezed\nstates we found macroscopic superpositions with a distance of up to\n$0.83\\pm0.02$ SNU. The proof of macroscopic quantum coherence was investigated\nwith respect to squeezing and purity of the states.",
    "arxiv_id": "quant-ph/0702215",
    "authors": [
      "Christoph Marquardt",
      "Ulrik L. Andersen",
      "Gerd Leuchs",
      "Yuishi Takeno",
      "Mitsuyoshi Yukawa",
      "Hidehiro Yonezawa",
      "Akira Furusawa"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.76.030101",
    "journal_ref": "Phys. Rev. A, 76 (3), 030101 (2007)",
    "title": "Experimental Demonstration of Macroscopic Quantum Coherence in Gaussian   States",
    "url": "https://arxiv.org/abs/quant-ph/0702215"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "6691071b-bce2-42ee-8dc0-4ff832a71884",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}