{
  "id": "2006.12340",
  "version": "v1",
  "published": "2020-06-22T15:34:35.000Z",
  "updated": "2020-06-22T15:34:35.000Z",
  "title": "Ultrafast Operations of a Hole Spin Qubit in Ge Quantum Dot",
  "authors": [
    "Ke Wang",
    "Gang Xu",
    "Fei Gao",
    "He Liu",
    "Rong-Long Ma",
    "Xin Zhang",
    "Ting Zhang",
    "Gang Cao",
    "Ting Wang",
    "Jian-Jun Zhang",
    "Xuedong Hu",
    "Hong-Wen Jiang",
    "Hai-Ou Li",
    "Guang-Can Guo",
    "Guo-Ping Guo"
  ],
  "comment": "14 pages,4 figures",
  "categories": [
    "cond-mat.mes-hall",
    "quant-ph"
  ],
  "abstract": "Strong spin-orbit coupling and relatively weak hyperfine interaction make quantum dots in germanium a promising candidate for rapid, all-electrically quantum control of spin qubit. Here, we report two different modes of quantum operation in a single spin-qubit based on holes in germanium hut wire. By selecting a proper branch of spin resonances mediated by spin-orbit interaction, a Rabi oscillation exceeding 540 MHz is observed at a small magnetic field of 100 mT. Furthermore, we perform two-axis control of the spin qubit by applying a phase-tunable microwave modulation. A dephasing time is measured by Ramsey spectroscopy, and further extended by dynamic decoupling. The qubit has a rather high quality-factor of 90, for nanowire-based spin qubits.Based on numerical calculation of the Rabi frequency of these two modes, we confirm that the ultrafast control speed is caused by the large spin-orbit coupling strength of holes in germanium.Our results demonstrate the potential to further control the spin qubit with a faster frequency to meet the requirement of Divincenzo's criteria for quantum gates, when the spin-orbit coupling is properly enhanced while maintaining good coherence in this system.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-06-22T15:34:35.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "hole spin qubit",
      "ge quantum dot",
      "ultrafast operations",
      "germanium hut wire",
      "relatively weak hyperfine interaction"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}