{
  "annotation_id": "f365accc-5d8f-4262-b34e-6af3f80bc4c0",
  "date_created": "2026-03-02T18:02:06.646000Z",
  "date_modified": "2026-03-02T18:02:06.646000Z",
  "file_hash": "359e40a91b5fbfc43e9aba69ab6453c8ed6197e69c7f87c2ae45478da147e0b0",
  "private": false,
  "record": {
    "abstract": "We investigate entanglement of two electron spins forming Cooper pairs in an\ns-wave superconductor. The two-electron space-spin density matrix is obtained\nfrom the BCS ground state using a two-particle Green\u0027s function. It is\ndemonstrated that a two spin state is not given by a spin singlet state but by\na Werner state. It is found that the entanglement length, within which two\nspins are entangled, is not the order of the coherence length but the order of\nthe Fermi wave length.",
    "arxiv_id": "quant-ph/0406013",
    "authors": [
      "Sangchul Oh",
      "Jaewan Kim"
    ],
    "categories": [
      "quant-ph",
      "cond-mat.mes-hall"
    ],
    "doi": "10.1103/PhysRevB.71.144523",
    "journal_ref": "Physical Review B 71, 144523 (2005)",
    "title": "Entanglement of electron spins in superconductors",
    "url": "https://arxiv.org/abs/quant-ph/0406013"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "8b0dab11-0e61-496a-9939-6da39efda1b3",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}