Physical Review X (May 2019)

Light-Induced Subpicosecond Lattice Symmetry Switch in MoTe_{2}

  • M. Y. Zhang,
  • Z. X. Wang,
  • Y. N. Li,
  • L. Y. Shi,
  • D. Wu,
  • T. Lin,
  • S. J. Zhang,
  • Y. Q. Liu,
  • Q. M. Liu,
  • J. Wang,
  • T. Dong,
  • N. L. Wang

DOI
https://doi.org/10.1103/PhysRevX.9.021036
Journal volume & issue
Vol. 9, no. 2
p. 021036

Abstract

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The recent development of ultrashort laser pulses allows for optical control of structural and electronic properties of complex quantum materials. The layered transition-metal dichalcogenide MoTe_{2}, which can crystallize into several different structures with distinct topological and electronic properties, provides possibilities to control or switch between different phases. In this study, we report a photoinduced subpicosecond structural transition between the type-II Weyl semimetal phase and normal-semimetal phase in bulk crystalline MoTe_{2} by using ultrafast pump-probe and time-resolved second-harmonic-generation spectroscopy. The phase transition is most clearly characterized by the dramatic change of the shear oscillation mode and the intensity loss of second-harmonic generation. This work opens up new possibilities for ultrafast manipulation of the topological properties of solids, enabling potentially practical applications for a topological switch device with ultrafast excitations.