{
  "annotation_id": "13c85653-4a19-432d-bd17-2b811bffb42e",
  "date_created": "2026-03-02T18:02:22.873000Z",
  "date_modified": "2026-03-02T18:02:22.873000Z",
  "file_hash": "1dc65e65fd4dcf75de53912681e96afbc1b83666a5a5c38c508073c7624c18c3",
  "private": false,
  "record": {
    "abstract": "Non-linear properties of quantum states, such as entropy or entanglement,\nquantify important physical resources and are frequently used in quantum\ninformation science. They are usually calculated from a full description of a\nquantum state, even though they depend only on a small number parameters that\nspecify the state. Here we extract a non-local and a non-linear quantity,\nnamely the Renyi entropy, from local measurements on two pairs of polarization\nentangled photons. We also introduce a \"phase marking\" technique which allows\nto select uncorrupted outcomes even with non-deterministic sources of entangled\nphotons. We use our experimental data to demonstrate the violation of entropic\ninequalities. They are examples of a non-linear entanglement witnesses and\ntheir power exceeds all linear tests for quantum entanglement based on all\npossible Bell-CHSH inequalities.",
    "arxiv_id": "quant-ph/0511187",
    "authors": [
      "Fabio Antonio Bovino",
      "Giuseppe Castagnoli",
      "Artur Ekert",
      "Pawel Horodecki",
      "Carolina Moura Alves",
      "Alexander Vladimir Sergienko"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevLett.95.240407",
    "title": "Direct measurement of non-linear properties of bipartite quantum states",
    "url": "https://arxiv.org/abs/quant-ph/0511187"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "4046ae9b-2779-4278-99a9-0ff343174df6",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}