{
  "id": "1302.1087",
  "version": "v1",
  "published": "2013-01-26T04:21:38.000Z",
  "updated": "2013-01-26T04:21:38.000Z",
  "title": "THz Generation and Detection on Dirac Fermions in Topological Insulators",
  "authors": [
    "C. W. Luo",
    "C. C. Lee",
    "H. -J. Chen",
    "C. M. Tu",
    "S. A. Ku",
    "W. Y. Tzeng",
    "T. T. Yeh",
    "M. C. Chiang",
    "H. J. Wang",
    "W. C. Chu",
    "J. -Y. Lin",
    "K. H. Wu",
    "J. Y. Juang",
    "T. Kobayashi",
    "C. -M. Cheng",
    "C. -H. Chen",
    "K. -D. Tsuei",
    "H. Berger",
    "R. Sankar",
    "F. C. Chou",
    "H. D. Yang"
  ],
  "comment": "5 pages, 4 figures, 1 table",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci"
  ],
  "abstract": "This study shows that a terahertz (THz) wave can be generated from the (001) surface of cleaved Bi$_{\\textrm{2}}$Se$_{\\textrm{3}}$ and Cu-doped Bi$_{\\textrm{2}}$Se$_{\\textrm{3}}$ single crystals using 800 nm femtosecond pulses. The generated THz power is strongly dependent on the carrier concentration of the crystals. An examination of the dependence reveals the two-channel free carrier absorption to which Dirac fermions are indispensable. Dirac fermions in Bi$_{\\textrm{2}}$Se$_{\\textrm{3}}$ are significantly better absorbers of THz radiation than bulk carriers at room temperature. Moreover, the characteristics of THz emission confirm the existence of a recently proposed surface phonon branch that is normalized by Dirac fermions.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2013-01-26T04:21:38.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dirac fermions",
      "thz generation",
      "topological insulators",
      "two-channel free carrier absorption",
      "nm femtosecond pulses"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2013arXiv1302.1087L"
    }
  }
}