{
  "annotation_id": "88739402-aaaa-4d66-b9c6-ea39d9be7b33",
  "date_created": "2026-03-02T18:02:31.096000Z",
  "date_modified": "2026-03-02T18:02:31.096000Z",
  "file_hash": "504496bd6702f9217a583e96ca3c459f7503491b2d65ca0db6c2e094fcb0d874",
  "private": false,
  "record": {
    "abstract": "We present a new approach to the analysis of entanglement in smooth bipartite\ncontinuous-variable states. One or both parties perform projective filterings\nvia preliminary measurements to determine whether the system is located in some\nregion of space; we study the entanglement remaining after filtering. For small\nregions, a two-mode system can be approximated by a pair of qubits and its\nentanglement fully characterized, even for mixed states. Our approach may be\nextended to any smooth bipartite pure state or two-mode mixed state, leading to\nnatural definitions of concurrence and negativity densities. For Gaussian\nstates both these quantities are constant throughout configuration space.",
    "arxiv_id": "quant-ph/0608121",
    "authors": [
      "H. -C. Lin",
      "A. J. Fisher"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.76.042320",
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "title": "Entanglement in general two-mode continuous-variable states: local   approach and mapping to a two-qubit system",
    "url": "https://arxiv.org/abs/quant-ph/0608121"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "3216d3b3-b229-4e12-99df-71c55fc18b14",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}