{
  "annotation_id": "3b873247-8edf-4ba8-966b-e91bd637d7ce",
  "date_created": "2026-03-02T18:01:37.955000Z",
  "date_modified": "2026-03-02T18:01:37.955000Z",
  "file_hash": "003e5909dbf492a2e159161d42cf2cf4e7f3992009e1388a4f76b70647d8ebba",
  "private": false,
  "record": {
    "abstract": "The general expression with the physical significance and positive definite\ncondition of the eigenvalues of $4\\times 4$ Hermitian and trace-one matrix are\nobtained. This implies that the eigenvalue problem of the $4\\times 4$ density\nmatrix is generally solved. The obvious expression of Peres\u0027 separability\ncondition for an arbitrary state of two qubits is then given out and it is very\neasy to use. Furthermore, we discuss some applications to the calculation of\nthe entanglement, the upper bound of the entanglement, and a model of the\ntransfer of entanglement in a qubit chain through a noisy channel.",
    "arxiv_id": "quant-ph/0002073",
    "authors": [
      "An Min Wang"
    ],
    "categories": [
      "quant-ph"
    ],
    "journal_ref": "Comm. Theor. Phys. Vol.42, p206 (2004) [a little revision]",
    "title": "Eigenvalues, Peres\u0027 separability condition and entanglement",
    "url": "https://arxiv.org/abs/quant-ph/0002073"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "543857b6-440a-4e5a-ad53-2ad052f72f58",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}