{
  "annotation_id": "cc4740b5-faca-4137-9c5a-e5ab7d09a62a",
  "date_created": "2026-03-02T18:02:30.990000Z",
  "date_modified": "2026-03-02T18:02:30.990000Z",
  "file_hash": "a3462874b646ceaa2799230830d1f27173ca3ce557169c3b3956b3565f6e24aa",
  "private": false,
  "record": {
    "abstract": "We study the non-equilibrium dynamics of a pair of qubits made of two-level\natoms separated in space with distance r and interacting with one common\nelectromagnetic field but not directly with each other. Our calculation makes a\nweak coupling assumption, but no Born or Markov approximation. We derived a\nnon-Markovian master equation for the evolution of the reduced density matrix\nof the two-qubit system after integrating out the electromagnetic field modes.\nIt contains a Markovian part with a Lindblad type operator and a nonMarkovian\ncontribution, the physics of which is the main focus of this study. We use the\nconcurrence function as a measure of quantum entanglement between the two\nqubits. Two classes of states are studied in detail: Class A is a one parameter\nfamily of states which are the superposition of the highest energy and Class B\nstates are linear combinations of the symmetric and the antisymmetric Bell\nstates. We obtain similar behavior for the Bell states as in earlier results\nderived by using the Born-Markov approximation. However, in the Class A states\nthe behavior is qualitatively different: under the non-Markovian evolution we\ndo not see sudden death of quantum entanglement and subsequent revivals, except\nwhen the qubits are sufficiently far apart. We provide explanations for such\ndifferences of behavior both between these two classes of states and between\nthe predictions from the Markov and non-Markovian dynamics. We also study the\ndecoherence of this two-qubit system and find that the decoherence rate in the\ncase of one qubit initially in an excited state does not change significantly\nwith the qubits separation whereas it does for the case when one qubit is\ninitially in the ground state.",
    "arxiv_id": "quant-ph/0610007",
    "authors": [
      "C. Anastopoulos",
      "S. Shresta",
      "B. L. Hu"
    ],
    "categories": [
      "quant-ph"
    ],
    "title": "Quantum Entanglement under Non-Markovian Dynamics of Two Qubits   Interacting with a common Electromagnetic Field",
    "url": "https://arxiv.org/abs/quant-ph/0610007"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "9c861981-8888-4658-8398-b1b6c434c93d",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}