{
  "id": "1608.04087",
  "version": "v1",
  "published": "2016-08-14T11:04:34.000Z",
  "updated": "2016-08-14T11:04:34.000Z",
  "title": "Resonant quenching of Raman scattering due to out-of-plane A$_{1g}$/A'$_1$ modes in few-layer MoTe$_2$",
  "authors": [
    "K. Gołasa",
    "M. Grzeszczyk",
    "M. R. Molas",
    "M. Zinkiewicz",
    "Ł. Bala",
    "K. Nogajewski",
    "M. Potemski",
    "A. Wysmołek",
    "A. Babiński"
  ],
  "comment": "19 pages, 6 figures",
  "categories": [
    "cond-mat.mes-hall"
  ],
  "abstract": "Temperature-dependent (5 K to 300 K) Raman scattering study of A$_{1g}$/A'$_1$ phonon modes associated with out-of-plane displacements of tellurium atoms with respect to molybdenum atoms in monolayer (1L), bilayer (2L), trilayer (3L), and tetralayer (4L) molybdenum ditelluride (MoTe$_2$) is reported. The $\\lambda$=632.8 nm (1.96 eV) and $\\lambda$=647.1 nm (1.91 eV) laser light excitation has been employed. The temperature evolution of the modes' intensity critically depends on the flake thickness. While in 1L MoTe2 the intensity slightly increases with decreasing temperature, a strongly non-monotonic dependence of the A$_{1g}$ mode intensity is observed in 2L MoTe$_2$. The intensity decreases with decreasing temperature down to 220 K and the A$_{1g}$ mode almost completely vanishes from the Stokes scattering spectrum in the temperature range between 160 K and 220 K. The peak recovers at lower temperatures and at T=5 K it becomes three times more intense that at room temperature. Similar non-monotonic intensity evolution is observed for the out-of-plane modes in 3L and 4L MoTe$_2$ in which tellurium atoms in all three layers vibrate in-phase. In contrast, the intensity of the other out-of-plane Raman-active mode, (in which vibrations of tellurium atoms in the central layer(s) of 3L (4L) MoTe2 are shifted by 180$^o$ with respect to the vibrations in outer layers), only weakly depends on temperature. The observed quenching of the Raman scattering is attributed to a destructive interference between the resonant and non-resonant contributions to the Raman scattering amplitude. The observed \"antiresonance\" is related to the electronic excitations at the M point of the Brillouin zone in few-layer MoTe$_2$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-08-14T11:04:34.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "raman scattering",
      "few-layer mote",
      "out-of-plane",
      "tellurium atoms",
      "resonant quenching"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 19,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}