{
  "annotation_id": "81f599b7-7fbe-4df0-9245-a028a1d13737",
  "date_created": "2026-03-02T18:02:07.053000Z",
  "date_modified": "2026-03-02T18:02:07.053000Z",
  "file_hash": "d016894ab85309f1e1d2d28688dac9242920fea5fb7a39325f2cb49b0a174fe8",
  "private": false,
  "record": {
    "abstract": "We investigate the entanglement properties of a one dimensional chain of spin\nqubits coupled via nearest neighbor interactions. The entanglement measure used\nis the n-concurrence, which is distinct from other measures on spin chains such\nas bipartite entanglement in that it can quantify \"global\" entanglement across\nthe spin chain. Specifically, it computes the overlap of a quantum state with\nits time-reversed state. As such this measure is well suited to study ground\nstates of spin chain Hamiltonians that are intrinsically time reversal\nsymmetric. We study the robustness of n-concurrence of ground states when the\ninteraction is subject to a time reversal antisymmetric magnetic field\nperturbation. The n-concurrence in the ground state of the isotropic XX model\nis computed and it is shown that there is a critical magnetic field strength at\nwhich the entanglement experiences a jump discontinuity from the maximum value\nto zero. The n-concurrence for thermal mixed states is derived and a threshold\ntemperature is computed below which the system has non zero entanglement.",
    "arxiv_id": "quant-ph/0406064",
    "authors": [
      "Gavin K. Brennen",
      "Stephen S. Bullock"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.70.052303",
    "journal_ref": "Physical Review A, 70, 052303 (2004).",
    "title": "Stability of global entanglement in thermal states of spin chains",
    "url": "https://arxiv.org/abs/quant-ph/0406064"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "ddf58191-c705-49e6-a6f6-ac7a6b6cc6b3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}