{
  "annotation_id": "696955c1-e53c-43a7-94ba-4c92d131e69d",
  "date_created": "2026-03-02T18:01:51.773000Z",
  "date_modified": "2026-03-02T18:01:51.773000Z",
  "file_hash": "006d352dd9a161479989b4c1d0bb770efcda300c6f9272ef9f537d4defb4d5e3",
  "private": false,
  "record": {
    "abstract": "The most general evolution of the density matrix of a quantum system with a\nfinite-dimensional state space is by stochastic maps which take a density\nmatrix linearly into the set of density matrices. These dynamical stochastic\nmaps form a linear convex set that may be viewed as supermatrices. The property\nof hermiticity of density matrices renders an associated supermatrix hermitian\nand hence diagonalizable. The positivity of the density matrix does not make\nthe associated supermatrix positive though. If the map itself is positive, it\nis called completely positive and they have a simple parameterization. This is\nextended to all positive (not completely positive) maps. A general dynamical\nmap that does not preserve the norm of the density matrices it acts on can be\nthought of as the contraction of a norm-preserving map of an extended system.\nThe reconstruction of such extended dynamics is also given.",
    "arxiv_id": "quant-ph/0205051",
    "authors": [
      "E. C. G. Sudarshan",
      "Anil Shaji"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/0305-4470/36/18/312",
    "journal_ref": "J. Phys. A, 36, 5073-5081 (2003)",
    "title": "Structure and Parametrization of Generic Stochastic Maps of Density   Matrices",
    "url": "https://arxiv.org/abs/quant-ph/0205051"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "46182514-06a2-4ca2-adee-7af29e0020cc",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}