{
  "annotation_id": "b483a914-a68c-48b3-8527-1c5859bc75c3",
  "date_created": "2026-03-02T18:01:59.538000Z",
  "date_modified": "2026-03-02T18:01:59.538000Z",
  "file_hash": "16c69ab36561941e9079be925362777d8b356dfe03d20fb2363b4cdda1fe3b6e",
  "private": false,
  "record": {
    "abstract": "We study the dynamics of a Heisenberg-XY spin chain with an unknown state\ncoded into one qubit or a pair of entangled qubits, with the rest of the spins\nbeing in a polarized state. The time evolution involves magnon excitations, and\nthrough them the entanglement is transported across the channel. For a large\nnumber of qubits, explicit formulae for the concurrences, measures for\ntwo-qubit entanglements, and the fidelity for recovering the state some\ndistance away are calculated as functions of time. Initial states with an\nentangled pair of qubits show better fidelity, which takes its first maximum\nvalue at earlier times, compared to initial states with no entangled pair. In\nparticular initial states with a pair of qubits in an unknown state (alpha\nup-up + beta down-down) are best suited for quantum state transport.",
    "arxiv_id": "quant-ph/0307135",
    "authors": [
      "V. Subrahmanyam"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1103/PhysRevA.69.034304",
    "journal_ref": "Phys. Rev. A69, 034304 (2004)",
    "title": "Entanglement dynamics and quantum state transport in spin chains",
    "url": "https://arxiv.org/abs/quant-ph/0307135"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "bf1d12a1-d672-422d-a8cf-988186b5a353",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}