{
  "id": "1006.5943",
  "version": "v3",
  "published": "2010-06-30T18:01:48.000Z",
  "updated": "2011-02-24T20:21:22.000Z",
  "title": "Suppression of Decoherence and Disentanglement by the Exchange Interaction",
  "authors": [
    "Amrit De",
    "Alex Lang",
    "Dong Zhou",
    "Robert Joynt"
  ],
  "doi": "10.1103/PhysRevA.83.042331",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.stat-mech",
    "quant-ph"
  ],
  "abstract": "Entangled qubit pairs can serve as a quantum memory or as a resource for quantum communication. The utility of such pairs is measured by how long they take to disentangle or decohere. To answer the question of whether qubit-qubit interactions can prolong entanglement, we calculate the dissipative dynamics of a pair of qubits coupled via the exchange interaction in the presence of random telegraph noise and $1/f$ noise. We show that for maximally entangled (Bell) states, the exchange interaction generally suppresses decoherence and disentanglement. This suppression is more apparent for random telegraph noise if the noise is non-Markovian, whereas for $1/f$ noise the exchange interaction should be comparable in magnitude to strongest noise source. The entangled singlet-triplet superposition state of 2 qubits ($\\psi_{\\pm}$ Bell state) can be protected by the interaction, while for the triplet-triplet state ($\\phi_{\\pm}$ Bell state), it is less effective. Thus the former is more suitable for encoding quantum information.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2011-02-24T20:21:22.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "03.67.Pp",
      "03.65.Yz",
      "05.40.-a"
    ],
    "keywords": [
      "exchange interaction",
      "random telegraph noise",
      "decoherence",
      "suppression",
      "disentanglement"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review A",
      "year": 2011,
      "month": "Apr",
      "volume": 83,
      "number": 4,
      "pages": "042331"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2011PhRvA..83d2331D"
    }
  }
}