{
  "annotation_id": "7fc89be4-8b17-4b9c-b678-14057233fb00",
  "date_created": "2026-03-02T18:02:45.147000Z",
  "date_modified": "2026-03-02T18:02:45.147000Z",
  "file_hash": "27093aa41de09b6be187782e6671b604905a6b9e2778654114116b4caacd578b",
  "private": false,
  "record": {
    "abstract": "Experiments have shown that individual photons penetrate an optical tunnel\nbarrier with an effective group velocity considerably greater than the vacuum\nspeed of light. The experiments were conducted with a two-photon parametric\ndown-conversion light source, which produced correlated, but random, emissions\nof photon pairs. The two photons of a given pair were emitted in slightly\ndifferent directions so that one photon passed through the tunnel barrier,\nwhile the other photon passed through the vacuum. The time delay for the\ntunneling photon relative to its twin was measured by adjusting the path length\ndifference between the two photons in a Hong-Ou-Mandel interferometer, in order\nto achieve coincidence detection. We found that the photon transit time through\nthe barrier was smaller than the twin photon\u0027s transit time through an equal\ndistance in vacuum, indicating that the process of tunneling in quantum\nmechanics is superluminal. Various conflicting theories of tunneling times are\ncompared with experiment.",
    "arxiv_id": "quant-ph/9811019",
    "authors": [
      "Raymond Y. Chiao"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1063/1.57888",
    "title": "Tunneling Times and Superluminality: a Tutorial",
    "url": "https://arxiv.org/abs/quant-ph/9811019"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "44e01605-d33e-41ea-b6ee-4f1627dfb1df",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}