{
  "id": "2107.00732",
  "version": "v1",
  "published": "2021-07-01T20:15:55.000Z",
  "updated": "2021-07-01T20:15:55.000Z",
  "title": "Impact of the valley orbit coupling on exchange gate for spin qubits in silicon quantum dots",
  "authors": [
    "Bilal Tariq",
    "Xuedong Hu"
  ],
  "comment": "15 pages, 11 Figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "The presence of degenerate conduction band valleys and how they are mixed by interfaces play critical roles in determining electron interaction and spectrum in a silicon nanostructure. Here we investigate how the valley phases affect the exchange interaction in a symmetric two-electron silicon double quantum dot. Through a configuration interaction calculation, we find that exchange splitting is suppressed at a finite value of valley phase difference between the two dots, and reaches its minimum value ({\\sim} 0) when the phase difference is {\\pi}. Such a suppression can be explained using the Hubbard model, through the valley-phase-dependent dressing by the doubly occupied states on the ground singlet and triplet states. The contributions of the higher orbital states also play a vital role in determining the value of the exchange energy in general, which is a crucial parameter for applications such as exchange gates for spin qubits.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-07-01T20:15:55.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "silicon quantum dots",
      "exchange gate",
      "spin qubits",
      "valley orbit coupling",
      "degenerate conduction band valleys"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}