Oxidation effect on WTe<sub>2</sub> 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)

*This work is supported by Robert Welch Foundation, F-1038. N.H.Jo and P.C.Canfield was supported by the U.S. DOE/BES, Division of Materials Sciences and Engineering under Contract No. DE-AC02-07CH11358. Na Hyun Jo is supported by the Gordon and Betty Moore Foundation EPiQS Initiative (Grant No. GBMF4411)

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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