{
  "id": "2202.13944",
  "version": "v1",
  "published": "2022-02-28T16:49:18.000Z",
  "updated": "2022-02-28T16:49:18.000Z",
  "title": "Coherence limitations in the optical control of the singlet-triplet qubit in a quantum dot molecule",
  "authors": [
    "Karol Kawa",
    "Tilmann Kuhn",
    "Paweł Machnikowski"
  ],
  "categories": [
    "cond-mat.mes-hall",
    "quant-ph"
  ],
  "abstract": "We analyze the optically driven dynamics of a qubit implemented on a singlet-triplet subspace of two-electron states in a self-assembled quantum dot molecule. We study two possible control schemes based on the coupling to an excited (four-particle) state either by two spectrally separated laser pulses or by a single spectrally broad pulse. We quantitatively characterize the imperfections of the qubit operation resulting from non-adiabatic evolution and from limited spectral selectivity in a real system, as compared to the ideal adiabatic Raman transfer of occupation in the $\\Lambda$-system. Next, we study the effects of decoherence induced by the coupling to the phonons of the surrounding crystal lattice and by radiative recombination. As a result, we are able to identify the optimization trade-offs between different sources of errors and indicate the most favorable conditions for quantum control of the singlet-triplet qubit in the two optical control schemes.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-02-28T16:49:18.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "singlet-triplet qubit",
      "optical control",
      "coherence limitations",
      "ideal adiabatic raman transfer",
      "control schemes"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}