{
  "id": "1612.08031",
  "version": "v1",
  "published": "2016-12-23T16:40:14.000Z",
  "updated": "2016-12-23T16:40:14.000Z",
  "title": "Exciton states in a circular graphene quantum dot: magnetic field induced intravalley to intervalley transition",
  "authors": [
    "L. L. Li",
    "M. Zarenia",
    "W. Xu",
    "H. M. Dong",
    "F. M. Peeters"
  ],
  "comment": "10 pages, 8 figures, to appear in Phys. Rev. B",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "The magnetic-field dependence of the energy spectrum, wave function, binding energy and oscillator strength of exciton states confined in a circular graphene quantum dot (CGQD) are obtained within the configuration interaction (CI) method. We predict that: (1) excitonic effects are very significant in the CGQD as a consequence of a combination of geometric confinement, magnetic confinement and reduced screening; (2) two types of excitons (intravalley and intervalley excitons) are present in the CGQD because of the valley degree of freedom in graphene; (3) the intravalley and intervalley exciton states display different magnetic-field dependencies due to the different electron-hole symmetries of the single-particle energy spectra; (4) with increasing magnetic field, the exciton ground state in the CGQD undergoes an intravalley to intervalley transition accompanied by a change of angular momentum; (5) the exciton binding energy does not increase monotonically with the magnetic field due to the competition between geometric and magnetic confinements; and (6) the optical transitions of the intervalley and intravalley excitons can be tuned by the magnetic field and valley-dependent excitonic transitions can be realized in CGQD.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-12-23T16:40:14.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "circular graphene quantum dot",
      "magnetic field induced intravalley",
      "exciton states",
      "intervalley transition",
      "magnetic confinement"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}