{
  "annotation_id": "e1f426d4-8d92-4346-a7ed-93f8c8a2c411",
  "date_created": "2026-03-02T18:02:36.797000Z",
  "date_modified": "2026-03-02T18:02:36.797000Z",
  "file_hash": "d7f34d527c9372b90d3ebf31281ef4005fc3d95e799adf09f3e9fba5541866fc",
  "private": false,
  "record": {
    "abstract": "In the non-linear optical process of type-II spontaneous parametric\ndown-conversion, we present on an experiment showing that the two-photon\ndetection amplitude of the down-converted beams does not generally reproduce\nthe transverse profile of the pump beam that carries non-zero orbital angular\nmomentum. We explain this observation by that orbital angular momentum is not\nconserved in the type-II non-linear process due to the broken rotational\nsymmetry of the Hamiltonian.",
    "arxiv_id": "quant-ph/0703212",
    "authors": [
      "Sheng Feng",
      "Chao-Hsiang Chen",
      "Geraldo A. Barbosa",
      "Prem Kumar"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1117/12.734118",
    "title": "Is orbital angular momentum always conserved in spontaneous parametric   down-conversion?",
    "url": "https://arxiv.org/abs/quant-ph/0703212"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "232ec1cb-ed75-47ae-93b9-cc1d474cd947",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}