{
  "id": "1510.07022",
  "version": "v1",
  "published": "2015-10-23T19:38:03.000Z",
  "updated": "2015-10-23T19:38:03.000Z",
  "title": "Exciton Diamagnetic Shifts and Valley Zeeman Effects in Monolayer WS$_2$ and MoS$_2$ to 65 Tesla",
  "authors": [
    "Andreas V. Stier",
    "Kathleen M. McCreary",
    "Berend T. Jonker",
    "Junichiro Kono",
    "Scott A. Crooker"
  ],
  "comment": "9 pages, 5 figures",
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci"
  ],
  "abstract": "We report circularly-polarized optical reflection spectroscopy of monolayer WS$_2$ and MoS$_2$ at low temperatures (4~K) and in high magnetic fields to 65~T. Both the A and the B exciton transitions exhibit a clear and very similar Zeeman splitting of approximately $-$230~$\\mu$eV/T ($g\\simeq -4$), providing the first measurements of the valley Zeeman effect and associated $g$-factors in monolayer transition-metal disulphides. These results complement and are compared with recent low-field photoluminescence measurements of valley degeneracy breaking in the monolayer diselenides MoSe$_2$ and WSe$_2$. Further, the very large magnetic fields used in our studies allows us to observe the small quadratic diamagnetic shifts of the A and B excitons in monolayer WS$_2$ (0.32 and 0.11~$\\mu$eV/T$^2$, respectively), from which we calculate exciton radii of 1.53~nm and 1.16~nm. When analyzed within a model of non-local dielectric screening in monolayer semiconductors, these diamagnetic shifts also constrain and provide estimates of the exciton binding energies (410~meV and 470~meV for the A and B excitons, respectively), further highlighting the utility of high magnetic fields for understanding new 2D materials.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-10-23T19:38:03.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "valley zeeman effect",
      "exciton diamagnetic shifts",
      "monolayer ws",
      "high magnetic fields",
      "circularly-polarized optical reflection spectroscopy"
    ],
    "publication": {
      "doi": "10.1038/ncomms10643",
      "journal": "Nature Communications",
      "year": 2016,
      "month": "Feb",
      "volume": 7,
      "pages": 10643
    },
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2016NatCo...710643S"
    }
  }
}