{
  "id": "1507.04040",
  "version": "v1",
  "published": "2015-07-14T22:29:40.000Z",
  "updated": "2015-07-14T22:29:40.000Z",
  "title": "Signatures of Bloch-band geometry on excitons: non-hydrogenic spectra in transition metal dichalcogenides",
  "authors": [
    "Ajit Srivastava",
    "Ataç Imamoğlu"
  ],
  "comment": "5 pages, 2 figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "The geometry of electronic bands in a solid can drastically alter single-particle charge and spin transport. We show here that collective optical excitations arising from Coulomb interactions also exhibit unique signatures of Berry curvature and quantum geometric tensor. A non-zero Berry curvature mixes and lifts the degeneracy of $l \\neq 0$ states, leading to a time-reversal-symmetric analog of the orbital Zeeman effect. The quantum geometric tensor, on the other hand, leads to $l$-dependent shifts of exciton states that is analogous to the Lamb shift. Our results provide an explanation of the non-hydrogenic exciton spectrum recently calculated for transition metal dichalcogenides. Numerically, we find a Berry curvature induced splitting of $\\sim 10$ meV between the $2p_x \\pm i2p_y$ states of WSe$_2$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-07-14T22:29:40.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "transition metal dichalcogenides",
      "non-hydrogenic spectra",
      "bloch-band geometry",
      "quantum geometric tensor",
      "signatures"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 5,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}