{
  "annotation_id": "5834d056-3bac-4c56-b95e-9d05d2bfc884",
  "date_created": "2026-03-02T18:01:45.197000Z",
  "date_modified": "2026-03-02T18:01:45.197000Z",
  "file_hash": "0321932c657a7c18fc29405f91c9a013666b2605d8acce6c84462cdb4ef48e63",
  "private": false,
  "record": {
    "abstract": "Purifying noisy entanglement is a protocol which can increase the\nentanglement of a mixed state (as a source)at expense of the entanglement of\nothers(as an ancilla)by collective measurement. A protocol with which one can\nget a pure entangled state from a mixed state is defined as purifying mixed\nstates. We address a basic question: can one get a pure entangled state from a\nmixed state? We give a necessary and sufficient condition of purifying a mixed\nstate by fit local operations and classical communication and show that for a\nclass of source states and ancilla states in arbitrary bipartite systems\npurifying mixed states is impossible by finite rounds of purifying protocols.\nFor $2\\otimes 2$ systems, it is proved that arbitrary states cannot be purified\nby individual measurement. The possible application and meaning of the\nconclusion are discussed.",
    "arxiv_id": "quant-ph/0110044",
    "authors": [
      "Ping-Xing Chen",
      "Lin-Mei Liang",
      "Cheng-Zu Li",
      "Ming-Qiu Huang"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.65.012317",
    "journal_ref": "Phys. Rev.A 65, (2002) 012317",
    "title": "Impossibility Criterion for Obtaining Pure Entangled States From Mixed   States By Purifying Protocols",
    "url": "https://arxiv.org/abs/quant-ph/0110044"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "37835414-759b-4f2a-a073-fedbd09d363e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}