{
  "id": "1706.04575",
  "version": "v1",
  "published": "2017-06-14T16:26:24.000Z",
  "updated": "2017-06-14T16:26:24.000Z",
  "title": "Scaling of the Quantum Anomalous Hall Effect as an Indicator of Axion Electrodynamics",
  "authors": [
    "S. Grauer",
    "K. M. Fijalkowski",
    "S. Schreyeck",
    "M. Winnerlein",
    "K. Brunner",
    "R. Thomale",
    "C. Gould",
    "L. W. Molenkamp"
  ],
  "comment": "4+6 pages, 5+9 figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "We report on the scaling behavior of V-doped (Bi,Sb)$_2$Te$_3$ samples in the quantum anomalous Hall regime for samples of various thickness. While previous quantum anomalous Hall measurements showed the same scaling as expected from a two-dimensional integer quantum Hall state, we observe a dimensional crossover to three spatial dimensions as a function of layer thickness. In the limit of a sufficiently thick layer, we find scaling behavior matching the flow diagram of two parallel conducting topological surface states of a three-dimensional topological insulator each featuring a fractional shift of $\\frac{1}{2} e^2/h$ in the flow diagram Hall conductivity, while we recover the expected integer quantum Hall behavior for thinner layers. This constitutes the observation of a distinct type of quantum anomalous Hall effect, resulting from $\\frac{1}{2} e^2/h$ Hall conductance quantization of three-dimensional topological insulator surface states, in an experiment which does not require decomposition of signal to separate the contribution of two surfaces. This provides a possible experimental link between quantum Hall physics and axion electrodynamics.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-06-14T16:26:24.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quantum anomalous hall effect",
      "axion electrodynamics",
      "integer quantum hall behavior",
      "topological insulator surface states",
      "conducting topological surface states"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 6,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}