Nonlinear Optical Effect of Impulsive Stimulated Raman Process in type-II Weyl Semimetal T<sub>d</sub>-WTe<sub>2 </sub>

ORAL

Abstract

Recent studies into Weyl semimetals with noncentrosymmetric crystal structures have revealed a wide range of second order nonlinear phenomena, including the polarization-selective photogalvanic effect and giant second harmonic generation. We here present a study of another second order nonlinear effect, impulsive stimulated Raman scattering, in the type II Weyl semimetal Td-WTe2. Using ultrafast time-resolved optical reflectivity measurements, we demonstrate a large number of coherent phonons excited through this impulsive stimulated Raman scattering process and identify polarization-dependent selection rules for these phonons based on a symmetry analysis of the crystal structure of the material. Further, we investigate the fluence dependence of the phonons and compare this dependence to fluence-dependent carrier dynamics.

*This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE 1256260. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

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Presenters

  • Elizabeth Drueke

    • Department of Physics, University of Michigan

Authors

  • Elizabeth Drueke

    • Department of Physics, University of Michigan

  • Junjie Yang

    • Department of Physics and Science of Advanced Materials Program, Central Michigan University
    • Central Michigan University
    • Department of Physics, Central Michigan University
    • Central Michigan Univ

  • Liuyan Zhao

    • Department of Physics, University of Michigan
    • University of Michigan
    • University of Michigan, Ann Arbor