{
  "annotation_id": "cbb4436b-35ec-4b56-9dba-72090c293232",
  "date_created": "2026-03-02T18:02:33.511000Z",
  "date_modified": "2026-03-02T18:02:33.511000Z",
  "file_hash": "739e4e1e7f2454a04e6114752a46a504d7368afae744f5ac3d96ed26a155e4d0",
  "private": false,
  "record": {
    "abstract": "Entanglement witnesses provide a standard tool for the analysis of\nentanglement in experiments. We investigate possible nonlinear entanglement\nwitnesses from several perspectives. First, we demonstrate that they can be\nused to show that the set of separable states has no facets. Second, we give a\nnew derivation of nonlinear witnesses based on covariance matrices. Finally, we\ninvestigate extensions to the multipartite case.",
    "arxiv_id": "quant-ph/0612108",
    "authors": [
      "Otfried G\u00fchne",
      "Norbert L\u00fctkenhaus"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/1742-6596/67/1/012004",
    "journal_ref": "J. Phys.: Conf. Ser. 67, 012004 (2007)",
    "title": "Nonlinear entanglement witnesses, covariance matrices and the geometry   of separable states",
    "url": "https://arxiv.org/abs/quant-ph/0612108"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "a934525e-d578-4233-a35f-b8d8e7fbd766",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}