{
  "annotation_id": "5f574115-be63-470f-bd2d-6966fbc62fb5",
  "date_created": "2026-03-02T18:02:31.043000Z",
  "date_modified": "2026-03-02T18:02:31.043000Z",
  "file_hash": "92d75efbaeddc945aa279ee7381c31ab422ae7c844a4fbaaa678fb2731b0906d",
  "private": false,
  "record": {
    "abstract": "We study the measurement for the unambiguous discrimination of two mixed\nquantum states that are described by density operators $\\rho_1$ and $\\rho_2$ of\nrank d, the supports of which jointly span a 2d-dimensional Hilbert space.\nBased on two conditions for the optimum measurement operators, and on a\ncanonical representation for the density operators of the states, two equations\nare derived that allow the explicit construction of the optimum measurement,\nprovided that the expression for the fidelity of the states has a specific\nsimple form. For this case the problem is mathematically equivalent to\ndistinguishing pairs of pure states, even when the density operators are not\ndiagonal in the canonical representation. The equations are applied to the\noptimum unambiguous discrimination of two mixed states that are similar states,\ngiven by $\\rho_2= U\\rho_1 U^{\\dag}$, and that belong to the class where the\nunitary operator U can be decomposed into multiple rotations in the d mutually\northogonal two-dimensional subspaces determined by the canonical\nrepresentation.",
    "arxiv_id": "quant-ph/0611087",
    "authors": [
      "Ulrike Herzog"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.75.052309",
    "title": "Optimum unambiguous discrimination of two mixed states and application   to a class of similar states",
    "url": "https://arxiv.org/abs/quant-ph/0611087"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "18b1bc07-8ce9-4bcc-b6d0-e78ed58ea032",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}