{
  "id": "2006.09351",
  "version": "v1",
  "published": "2020-06-16T17:46:31.000Z",
  "updated": "2020-06-16T17:46:31.000Z",
  "title": "Helical Edge States and Quantum Phase Transitions in Tetralayer Graphene",
  "authors": [
    "Shi Che",
    "Yanmeng Shi",
    "Jiawei Yang",
    "Haidong Tian",
    "Ruoyu Chen",
    "Takashi Taniguchi",
    "Kenji Watanabe",
    "Dmitry Smirnov",
    "Chun Ning Lau",
    "Efrat Shimshoni",
    "Ganpathy Murthy",
    "Herbert A. Fertig"
  ],
  "comment": "Accepted by PRL",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci"
  ],
  "abstract": "Helical conductors with spin-momentum locking are promising platforms for Majorana fermions. Here we report observation of two topologically distinct phases supporting helical edge states in charge neutral Bernal-stacked tetralayer graphene in Hall bar and Corbino geometries. As the magnetic field B and out-of-plane displacement field D are varied, we observe a phase diagram consisting of an insulating phase and two metallic phases, with 0, 1 and 2 helical edge states, respectively. These phases are accounted for by a theoretical model that relates their conductance to spin-polarization plateaus. Transitions between them arise from a competition among inter-layer hopping, electrostatic and exchange interaction energies. Our work highlights the complex competing symmetries and the rich quantum phases in few-layer graphene.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-06-16T17:46:31.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quantum phase transitions",
      "neutral bernal-stacked tetralayer graphene",
      "supporting helical edge states",
      "phases supporting helical edge",
      "distinct phases supporting helical"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}