{
  "annotation_id": "c8d83904-74ef-443c-81f8-303fe964180d",
  "date_created": "2026-03-02T18:01:49.452000Z",
  "date_modified": "2026-03-02T18:01:49.452000Z",
  "file_hash": "d1dd57805f7a011be810341ff9f440955a76e3db0b792ae8422b712d08d0ce02",
  "private": false,
  "record": {
    "abstract": "We study the entanglement of thermal and ground states in Heisernberg $XX$\nqubit rings with a magnetic field. A general result is found that for\neven-number rings pairwise entanglement between nearest-neighbor qubits is\nindependent on both the sign of exchange interaction constants and the sign of\nmagnetic fields. As an example we study the entanglement in the four-qubit\nmodel and find that the ground state of this model without magnetic fields is\nshown to be a four-body maximally entangled state measured by the $N$-tangle.",
    "arxiv_id": "quant-ph/0203141",
    "authors": [
      "Xiaoguang Wang"
    ],
    "categories": [
      "quant-ph",
      "cond-mat.mes-hall"
    ],
    "doi": "10.1103/PhysRevA.66.034302",
    "journal_ref": "Phys. Rev. A 66, 034302 (2002).",
    "title": "Thermal and ground-state entanglement in Heisenberg XX qubit rings",
    "url": "https://arxiv.org/abs/quant-ph/0203141"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "a472ed69-edab-43d5-a410-6931719e5cb3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}