{
  "id": "1705.02110",
  "version": "v1",
  "published": "2017-05-05T07:43:36.000Z",
  "updated": "2017-05-05T07:43:36.000Z",
  "title": "Charged excitons in monolayer WSe$_2$: experiment and theory",
  "authors": [
    "E. Courtade",
    "M. Semina",
    "M. Manca",
    "M. M. Glazov",
    "C. Robert",
    "F. Cadiz",
    "G. Wang",
    "T. Taniguchi",
    "K. Watanabe",
    "M. Pierre",
    "W. Escoffier",
    "E. L. Ivchenko",
    "P. Renucci",
    "X. Marie",
    "T. Amand",
    "B. Urbaszek"
  ],
  "comment": "12 pages, 6 figures, 2 tables",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci",
    "cond-mat.other"
  ],
  "abstract": "Charged excitons, or X$^{\\pm}$-trions, in monolayer transition metal dichalcogenides have binding energies of several tens of meV. Together with the neutral exciton X$^0$ they dominate the emission spectrum at low and elevated temperatures. We use charge tunable devices based on WSe$_2$ monolayers encapsulated in hexagonal boron nitride, to investigate the difference in binding energy between X$^+$ and X$^-$ and the X$^-$ fine structure. We find in the charge neutral regime, the X$^0$ emission accompanied at lower energy by a strong peak close to the longitudinal optical (LO) phonon energy. This peak is absent in reflectivity measurements, where only the X$^0$ and an excited state of the X$^0$ are visible. In the $n$-doped regime, we find a closer correspondence between emission and reflectivity as the trion transition with a well-resolved fine-structure splitting of 6~meV for X$^-$ is observed. We present a symmetry analysis of the different X$^+$ and X$^-$ trion states and results of the binding energy calculations. We compare the trion binding energy for the $n$-and $p$-doped regimes with our model calculations for low carrier concentrations. We demonstrate that the splitting between the X$^+$ and X$^-$ trions as well as the fine structure of the X$^-$ state can be related to the short-range Coulomb exchange interaction between the charge carriers.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-05-05T07:43:36.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "charged excitons",
      "monolayer wse",
      "binding energy",
      "short-range coulomb exchange interaction",
      "monolayer transition metal dichalcogenides"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}