{
  "id": "2211.17240",
  "version": "v1",
  "published": "2022-11-30T18:43:37.000Z",
  "updated": "2022-11-30T18:43:37.000Z",
  "title": "Half-integer conductance plateau at the $ν= 2/3$ fractional quantum Hall state in a quantum point contact",
  "authors": [
    "James Nakamura",
    "Shuang Liang",
    "Geoffrey C. Gardner",
    "Michael J. Manfra"
  ],
  "comment": "9+3 pages, 4+4 figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "The $\\nu = 2/3$ fractional quantum Hall state is the hole-conjugate state to the primary Laughlin $\\nu = 1/3$ state. We investigate transmission of edge states through quantum point contacts fabricated on a GaAs/AlGaAs heterostructure designed to have a sharp confining potential. When a small but finite bias is applied, we observe an intermediate conductance plateau with $G = 0.5 \\frac{e^2}{h}$. This plateau is observed in multiple QPCs, and persists over a significant range of magnetic field, gate voltage, and source-drain bias, making it a robust feature. Using a simple model which considers scattering and equilibration between counterflowing charged edge modes, we find this half-integer quantized plateau to be consistent with full reflection of an inner counterpropagating -1/3 edge mode while the outer integer mode is fully transmitted. In a QPC fabricated on a different heterostructure which has a softer confining potential, we instead observe an intermediate conductance plateau at $G = \\frac{1}{3} \\frac{e^2}{h}$. These results provide support for a model at $\\nu = 2/3$ in which the edge transitions from a structure having an inner upstream -1/3 charge mode and outer downstream integer mode to a structure with two downstream 1/3 charge modes when the confining potential is tuned from sharp to soft and disorder prevails.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-11-30T18:43:37.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "fractional quantum hall state",
      "quantum point contact",
      "half-integer conductance plateau",
      "intermediate conductance plateau",
      "confining potential"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 3,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}