{
  "id": "2007.14712",
  "version": "v1",
  "published": "2020-07-29T09:47:06.000Z",
  "updated": "2020-07-29T09:47:06.000Z",
  "title": "Valley lifetimes of conduction band electrons in monolayer WSe$_2$",
  "authors": [
    "Manfred Ersfeld",
    "Frank Volmer",
    "Lars Rathmann",
    "Luca Kotewitz",
    "Maximilian Heithoff",
    "Mark Lohmann",
    "Bowen Yang",
    "Kenji Watanabe",
    "Takashi Taniguchi",
    "Ludwig Bartels",
    "Jing Shi",
    "Christoph Stampfer",
    "Bernd Beschoten"
  ],
  "comment": "5 pages, 3 figures",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci"
  ],
  "abstract": "One of the main tasks in the investigation of 2-dimensional transition metal dichalcogenides is the determination of valley lifetimes. In this work, we combine time-resolved Kerr rotation with electrical transport measurements to explore the gate-dependent valley lifetimes of free conduction band electrons of monolayer WSe$_2$. When tuning the Fermi energy into the conduction band we observe a strong decrease of the respective valley lifetimes which is consistent with both spin-orbit and electron-phonon scattering. We explain the formation of a valley polarization by the scattering of optically excited valley polarized bright trions into dark states by intervalley scattering. Furthermore, we show that the conventional time-resolved Kerr rotation measurement scheme has to be modified to account for photo-induced gate screening effects. Disregarding this adaptation can lead to erroneous conclusions drawn from gate-dependent optical measurements and can completely mask the true gate-dependent valley dynamics.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-07-29T09:47:06.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "conduction band electrons",
      "valley lifetimes",
      "monolayer wse",
      "kerr rotation measurement scheme",
      "time-resolved kerr rotation measurement"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}