{
  "id": "2405.16944",
  "version": "v1",
  "published": "2024-05-27T08:37:16.000Z",
  "updated": "2024-05-27T08:37:16.000Z",
  "title": "Even- and Odd-denominator Fractional Quantum Anomalous Hall Effect in Graphene Moire Superlattices",
  "authors": [
    "Jian Xie",
    "Zihao Huo",
    "Xin Lu",
    "Zuo Feng",
    "Zaizhe Zhang",
    "Wenxuan Wang",
    "Qiu Yang",
    "Kenji Watanabe",
    "Takashi Taniguchi",
    "Kaihui Liu",
    "Zhida Song",
    "X. C. Xie",
    "Jianpeng Liu",
    "Xiaobo Lu"
  ],
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.str-el"
  ],
  "abstract": "Fractional quantum anomalous hall effect (FQAHE), a transport effect with fractionally quantized Hall plateau emerging under zero magnetic field, provides a radically new opportunity to engineer topological quantum electronics. By construction of topological flat band with moire engineering, intrinsic FQAHE has been observed in twisted MoTe2 system and rhombohedral pentalayer graphene/hBN moire superlattices with anomalous Hall resistivity quantization number C <= 2/3 including the gapless composite Fermi-liquid state with C = 1/2. Here we experimentally demonstrate a new system of rhombohedral hexalayer graphene (RHG)/hBN moire superlattices showing both fractional and integer quantum anomalous Hall effects when the lowest flat Chern band is fractionally and fully filled at zero magnetic field. The zero-field Hall resistance Rho_xy = h/Ce2 is quantized to values corresponding to C = 3/5, 2/3, 5/7, 3/4, 7/9 and 1 at moire filling factors v = 3/5, 2/3, 5/7, 3/4, 7/9 and 1, respectively. Particularly, the C = 3/4 FQAHE state at v = 3/4 moire filling featuring a minimum of longitudinal resistance Rho_xx and fractionally quantized Hall resistance Rho_xy = 4h/3e2, is observed for the first time under zero magnetic field. Such a state may be similar to the C = 3/4 fractional quantum hall (FQHE) state recently observed at high magnetic fields9,10 and possibly host fractional charge excitations obeying non-Abelian statistics. By tuning the electrical and magnetic fields at 0 < v < 1, we have observed a sign reversal of the Hall resistivity for v = 2/3 state, indicating a transition from quasi-electron-like excitations to quasi-hole ones. Our experiment has established RHG/hBN moire superlattices a promising platform to explore quasi-particles with fractional charge excitations and non-Abelian anyons at zero magnetic field.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-05-27T08:37:16.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "fractional quantum anomalous hall effect",
      "odd-denominator fractional quantum anomalous hall",
      "fractional charge excitations",
      "zero magnetic field",
      "graphene moire superlattices"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}