Investigating the Energy Dependent Photogalvanic Effect in the Type-II Weyl Semimetal NbIrTe<sub>4</sub>

ORAL

Abstract

We explore the photogalvanic effect in NbIrTe4 , a type II Weyl semimetal. NbIrTe4 exhibits 8 pairs of Weyl nodes which are monopoles of Berry curvature with opposite ±1 chiralities. We measured the photoresponse for a full rotation of a quarter wave plate for energies ranging from 0.3 to 1 eV. The Photothermoelectric (PT), and Circular (CPGE) and Linear (LPGE) Photogalvanic responses were extracted by fitting the angular dependence of the signal. The PT response shows an onset at an energy at 0.3 eV, consistent with DFT calculations. The LPGE response is relatively constant over this energy range, while the CPGE response shows a strong increase at low energies as the excitation approaches the Weyl nodes at the Fermi energy. Surprisingly, a strong peak in the CPGE response is also seen in the range 0.5 to 0.7 eV. This suggests that the CPGE response may be enhanced by a transition between bands near the Weyl point and a higher lying state.

*We acknowledge the support of NSF grants DMR 1507844, 1531373, 1505549 and ECCS 1509706, and the NSF of China through grant 11674278.

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Presenters

  • Seyyedesadaf Pournia

    • Univ of Cincinnati
    • Department of Physics, University of Cincinnati

Authors

  • Seyyedesadaf Pournia

    • Univ of Cincinnati
    • Department of Physics, University of Cincinnati

  • Giriraj Jnawali

    • Univ of Cincinnati
    • Department of Physics, University of Cincinnati

  • Iraj Abbasian Shojaei

    • Univ of Cincinnati
    • Department of Physics, University of Cincinnati

  • Samuel Linser

    • Univ of Cincinnati
    • Department of Physics, University of Cincinnati

  • Howard Jackson

    • Univ of Cincinnati

  • Leigh M Smith

    • Univ of Cincinnati
    • Department of Physics, University of Cincinnati
    • Physics, University of Cincinnati

  • Congcong Le

    • Kavli Institute of Theoretical Sciences
    • Kavli Institute of Theoretical Sciences, University of the Chinese Academy of Sciences

  • Fu-Chun Zhang

    • Kavli Institute of Theoretical Sciences, University of Chinese Academy of Sciences
    • University of Hong Kong
    • Kavli Institute of Theoretical Sciences, University of the Chinese Academy of Sciences
    • Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences

  • Stephen Wilson

    • University of California, Santa Barbara
    • Materials Department, University of California, Santa Barbara
    • Materials Engineering, University of California, Santa Barbara
    • California NanoSystems Institute/Materials, University of California, Santa Barbara

  • Brenden Ortiz

    • University of California, Santa Barbara
    • Materials Engineering, University of California, Santa Barbara
    • Colorado School of Mines
    • California NanoSystems Institute/Materials, University of California, Santa Barbara