Oxidation effect on WTe2 using optical second harmonic generation

ORAL

Abstract

A transition metal dichalcogenide WTe2 has recently drawn many researchers’ attention because this material is Type-II Weyl semimetal in bulk1 and it is a topological insulator in a monolayer at low temperature2.
This material is known to be particularly sensitive to oxidation, which could alter its electronic and mechanical properties. Optical Second Harmonic Generation (SHG) microscopy is a good way to probe the small change at the surface due to its hypersensitivity to the structural changes. We used Ti:Sapphire laser, with 76 MHz repetition rate and 150 fs pulse, to see the oxidation effect on the rotational anisotropic SHG at a discrete oxidation level. We found out that the oxidation greatly affects SHG intensities in s-in/s-out polarization configuration. In this talk, I will be presenting a systematic study of oxidation effect on the bulk WTe2 as well as its spectroscopic response.

1 Y. Wu et al., Phys. Rev. B 94, 121113(R) (2016)
2 Z. Fei et al., Nat. Phys. 13, 677 (2017)

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Presenters

  • Yujin Cho

    University of Texas at Austin

Authors

  • Yujin Cho

    University of Texas at Austin

  • Na Hyun Jo

    Iowa State University, Iowa State University and Ames Laboratory, Ames Laboratory and Department of Physics & Astronomy, Iowa State University, Ames, IA 50010, USA, Department of Physics & Astronomy, Iowa State University, Department of Physics and Astronomy, Iowa State University, Department of physics and astronomy, Iowa State University/Ames Laboratory, Physics, Iowa State University/Ames Laboratory

  • Paul Canfield

    Ames Laboratory and Dept. of Physics, Iowa State University, Ames Laboratory, U.S. DOE, Iowa State University, Ames, Iowa 50011, USA., Ames Laboratory, Iowa State University, Department of Physics, Iowa State University, Ames Laboratory, Ames, Iowa 50011, USA, Ames Laboratory, Iowa State University, Ames Laboratory/Iowa State University, Iowa State University and Ames Laboratory, Ames Laboratory and Iowa State University, Ames, IA, USA, Ames Laboratory and Dept. of Phys. and Astro.,, Iowa State Univ., Ames Laboratory and Department of Physics & Astronomy, Iowa State University, Ames, IA 50010, USA, Ames Lab & Dept of Physics and Astronomy, Iowa State University, Department of Physics & Astronomy, Iowa State University, Department of physics and astronomy, Iowa State University/Ames Laboratory, Physics, Iowa State University/Ames Laboratory, Ames Laboratory & Iowa State University, Physics, Iowa State University

  • Michael C Downer

    The University of Texas at Austin, Physics, University of Texas at Austin, University of Texas at Austin