{
  "id": "1203.0705",
  "version": "v2",
  "published": "2012-03-04T04:32:27.000Z",
  "updated": "2012-06-19T05:52:40.000Z",
  "title": "Valley-Polarized Metals and Quantum Anomalous Hall Effect in Silicene",
  "authors": [
    "Motohiko Ezawa"
  ],
  "comment": "4 pages, 4 figures, to be published in Phys. Rev. Lett",
  "journal": "Phys. Rev. Lett. 109, 055502 (2012)",
  "doi": "10.1103/PhysRevLett.109.055502",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci"
  ],
  "abstract": "Silicene is a monolayer of silicon atoms forming a two-dimensional honeycomb lattice, which shares almost every remarkable property with graphene. The low energy structure of silicene is described by Dirac electrons with relatively large spin-orbit interactions due to its buckled structure. The key observation is that the band structure is controllable by applying the electric field to a silicene sheet. We explore the phase diagram of silicene together with exchange field $M$ and by applying electric field $E_{z}$. There appear quantum anomalous Hall (QAH) insulator, valley polarized metal (VPM), marginal valley polarized metal (M-VPM), quantum spin Hall (QSH) insulator and band insulator (BI). They are characterized by the Chern numbers and/or by the edge modes of a nanoribbon. It is intriguing that electrons have been moved from a conduction band at the K point to a valence band at the K' point for $E_{z}>0$ in the VPM. We find in the QAH phase that flat gapless edge modes emerge and that spins form a momentum-space skyrmion to yield the Chern number. It is remarkable that a topological quantum phase transition can be induced simply by changing electric field in a single silicene sheet.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2012-06-19T05:52:40.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "81.05.ue",
      "72.25.Dc",
      "72.80.Vp",
      "73.20.At"
    ],
    "keywords": [
      "quantum anomalous hall effect",
      "valley-polarized metals",
      "electric field",
      "valley polarized metal",
      "flat gapless edge modes emerge"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review Letters",
      "year": 2012,
      "month": "Aug",
      "volume": 109,
      "number": 5,
      "pages": "055502"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2012PhRvL.109e5502E"
    }
  }
}