{
  "annotation_id": "8b922409-4489-45a6-9a64-f6b3cfaf483c",
  "date_created": "2026-03-02T18:02:34.588000Z",
  "date_modified": "2026-03-02T18:02:34.588000Z",
  "file_hash": "a20e8bad24b464a46f2ed78111f1570f16b3692b37f3dcf013ac28a7cc191d7b",
  "private": false,
  "record": {
    "abstract": "We investigate macroscopic entanglement in an infinite XX spin-1/2 chain with\nstaggered magnetic field, B_l=B+e^{-i\\pi l}b. Using single-site entropy and by\nconstructing an entanglement witness, we search for the existence of\nentanglement when the system is at absolute zero, as well as in thermal\nequilibrium. Although the role of the alternating magnetic field b is, in\ngeneral, to suppress entanglement as do B and T, we find that when T=0,\nintroducing b allows the existence of entanglement even when the uniform\nmagnetic field B is arbitrarily large. We find that the region and the amount\nof entanglement in the spin chain can be enhanced by a staggered magnetic\nfield.",
    "arxiv_id": "quant-ph/0701013",
    "authors": [
      "Jenny Hide",
      "Wonmin Son",
      "Ian Lawrie",
      "Vlatko Vedral"
    ],
    "categories": [
      "quant-ph",
      "cond-mat.stat-mech"
    ],
    "doi": "10.1103/PhysRevA.76.022319",
    "journal_ref": "Phys. Rev. A 76, 022319 (2007)",
    "title": "Witnessing Macroscopic Entanglement in a Staggered Magnetic Field",
    "url": "https://arxiv.org/abs/quant-ph/0701013"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "ec581f24-f3ec-4c4b-9751-92f7aaac6b79",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}