Anisotropic Linear Optical Properties and Optical Resonances in Weyl Semimetals

ORAL

Abstract

Since the first experimental discovery of Weyl semimetals, TaAs and NbAs have attracted significant attention due to their broken inversion symmetry and topological properties. Optical characterization serves as a powerful tool to probe electronic transitions in these systems. To understand optical response as a function of wavelength, the anisotropic dielectric functions and complex refractive indices serve as fundamental properties and vital pieces of the puzzle.

Here, we demonstrate a comprehensive study of anisotropic dielectric functions of TaAs and NbAs by combining spectroscopic ellipsometry and density functional theory (DFT). The complete set of Lorentz oscillators reveals complicated resonances in the system. Multiple resonances are observed near several probing wavelengths, enhancing the optical response. Furthermore, the contributions by two types of Weyl points to dielectric functions show dominating response in low energy regions but are insignificant above 1 eV compared to the contributions from trivial bands.

*The authors acknowledge support by the NSF MRSEC Center for Nanoscale Science (DMR-2011839), the DOE under grant no. DE-SC0012375, the Army Research Office under grant no. DE-SC0012375, and NSF DMREF program under the award NSF DMREF project DMREF-1629457.

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Presenters

  • Rui Zu

    • Material Science and Engineering, Pennsylvania State University
    • Department of Materials Science and Engineering, Pennsylvania State University

Authors

  • Rui Zu

    • Material Science and Engineering, Pennsylvania State University
    • Department of Materials Science and Engineering, Pennsylvania State University

  • Mingqiang Gu

    • Department of Physics, Shenzhen Institute for Quantum Science and Engineering (SIQSE), Southern University of Science and Technology

  • Lujin Min

    • Department of Material Science and Engineering, Penn State University
    • Department of Physics, Pennsylvania State University
    • Physics, Pennsylvania State University
    • Pennsylvania State University
    • Department of Materials Science and Engineering, Pennsylvania State University

  • Chaowei Hu

    • University of California, Los Angeles
    • Physics, University of California, Los Angeles
    • Physics and Astronomy Department, University of California, Los Angeles
    • Department of Physics and Astronomy, University of California, Los Angeles

  • Ni Ni

    • University of California, Los Angeles
    • Physics, University of California, Los Angeles
    • Physics and Astronomy Department, University of California, Los Angeles
    • Department of Physics and Astronomy, University of California, Los Angeles

  • Zhiqiang Mao

    • Pennsylvania State University
    • Department of Physics, Penn State University
    • The Pennsylvania State University
    • Penn State University
    • Physics, Penn State University
    • Department of Physics, Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Physics, Pennsylvania State University
    • Department of Materials Science and Engineering, Pennsylvania State University

  • James M Rondinelli

    • Northwestern University
    • McCormick School of Engineering, Department of Materials Science and Engineering, Northwestern University
    • Department of Materials Science and Engineering, Northwestern University

  • Venkatraman Gopalan

    • Pennsylvania State University
    • Material Science and Engineering, Pennsylvania State University
    • Department of Material Science and Engineering, Penn State University
    • Department of Materials Science and Engineering, Pennsylvania State University
    • Materials Science and Engineering, Pennsylvania State University