{
  "id": "1302.0983",
  "version": "v2",
  "published": "2013-02-05T10:31:07.000Z",
  "updated": "2013-05-30T04:56:58.000Z",
  "title": "Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting",
  "authors": [
    "C. H. Yang",
    "A. Rossi",
    "R. Ruskov",
    "N. S. Lai",
    "F. A. Mohiyaddin",
    "S. Lee",
    "C. Tahan",
    "G. Klimeck",
    "A. Morello",
    "A. S. Dzurak"
  ],
  "comment": "17 pages, 6 figures (main manuscript and supplementary material)",
  "journal": "Nature Communications 4:2069 (2013)",
  "doi": "10.1038/ncomms3069",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "Although silicon is a promising material for quantum computation, the degeneracy of the conduction band minima (valleys) must be lifted with a splitting sufficient to ensure formation of well-defined and long-lived spin qubits. Here we demonstrate that valley separation can be accurately tuned via electrostatic gate control in a metal-oxide-semiconductor quantum dot, providing splittings spanning 0.3 - 0.8 meV. The splitting varies linearly with applied electric field, with a ratio in agreement with atomistic tight-binding predictions. We demonstrate single-shot spin readout and measure the spin relaxation for different valley configurations and dot occupancies, finding one-electron lifetimes exceeding 2 seconds. Spin relaxation occurs via phonon emission due to spin-orbit coupling between the valley states, a process not previously anticipated for silicon quantum dots. An analytical theory describes the magnetic field dependence of the relaxation rate, including the presence of a dramatic rate enhancement (or hot-spot) when Zeeman and valley splittings coincide.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2013-05-30T04:56:58.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "silicon quantum dot",
      "tunable valley splitting",
      "spin-valley lifetimes",
      "demonstrate single-shot spin readout",
      "metal-oxide-semiconductor quantum dot"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "Nature Communications",
      "year": 2013,
      "month": "Jun",
      "volume": 4,
      "pages": 2069
    },
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2013NatCo...4E2069Y"
    }
  }
}