The study of nonlinear responses in the chiral Weyl semimetal CoSi

ORAL

Abstract

The study of nonlinear optical and optoelectronic properties in Weyl semimetals has attracted much interest since the first observation of giant anisotropic second harmonic generation (SHG) in the type-I Weyl semimetal TaAs. The recently discovered class of chiral Weyl semimetals adds a unique perspective to this research because the lack of mirror symmetries allows for the energy separation of paired Weyl points. This separation allows light of micron-scale wavelengths to be used to directly probe one of the two paired Weyl cones, which is not possible in the more familiar type-I and type-II Weyl semimetals. In this talk, I will present our experimental study of two second order nonlinear effects, SHG and photocurrent generation, in an archetypal chiral Weyl semimetal, CoSi. I will quantify these effects and compare their strengths to observations of previously studied nonlinear crystals. Finally, I will apply field-symmetry-based arguments to distinguish between the AC effect of SHG and the DC effects of the shift current and circular photogalvanic effect.

*The speaker acknowledges support by the NSF Graduate Research Fellowship Program under grant no. DGE-1256260.

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Presenters

  • Elizabeth Drueke

    • Physics, University of Michigan
    • University of Michigan
    • Physics Department, University of Michigan

Authors

  • Elizabeth Drueke

    • Physics, University of Michigan
    • University of Michigan
    • Physics Department, University of Michigan

  • Rachel Owen

    • Physics, University of Michigan
    • University of Michigan
    • Physics Department, University of Michigan

  • Matthew W Day

    • Physics, University of Michigan
    • University of Michigan

  • Yiming Gong

    • University of Michigan

  • Kelsey Bates

    • Physics, University of Michigan
    • University of Michigan

  • Grace C Kerber

    • University of Michigan

  • Lu Chen

    • University of Michigan

  • Chenghe Li

    • Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China

  • Shangjie Tian

    • Renmin University of China
    • Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China

  • Hechang Lei

    • Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China

  • Lu Li

    • University of Michigan

  • Steven Thomas Cundiff

    • Physics, University of Michigan
    • University of Michigan
    • Department of Physics, University of Michigan
    • Physics Department, University of Michigan

  • Liuyan Zhao

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