Spatially Dispersive Circular Photogalvanic Effect in Weyl Semimetals

ORAL

Abstract

We observe a circulating photocurrent in type-II Weyl semimetals MoTe2/Mo0.9W0.1Te2, driven by circularly polarized light at normal incidence. This effect occurs exclusively in the Weyl phase and crucially we find that it is associated with a spatially inhomogeneous beam profile. We assign this response to spatially dispersive contribution to the circular photogalvanic effect (s-CPGE). We systematically analyze the microscopic mechanism of this photocurrent by calculating the quantum density matrix to first order in spatial gradients and second order in the electric field. We find that the observed s-CPGE is dominated by terms in the response function that are non-zero only in the inversion broken Weyl phase. We demonstrate our finding by numerical calculations of its frequency dependence using a minimal model of an inversion broken Weyl semimetal and use the calculation to find low and high frequency scaling behavior of the photocurrent.

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Presenters

  • Zhurun Ji

    • Univ of Pennsylvania

Authors

  • Zhurun Ji

    • Univ of Pennsylvania

  • Zachariah Addison

    • Physics & Astronomy, University of Pennsylvania
    • Univ of Pennsylvania

  • Gerui Liu

    • Univ of Pennsylvania

  • Wenjing Liu

    • Univ of Pennsylvania

  • Peng Yu

    • Nanyang Technological University
    • School of Materials Science and Engineering, Nanyang Technological University

  • Zheng Liu

    • Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University
    • Nanyang Technological University
    • School of Materials Science & Engineering, Nanyang Technological University
    • School of Materials Science and Engineering, Nanyang Technological University

  • Andrew Rappe

    • Univ of Pennsylvania
    • Chemistry, University of Pennsylvania
    • Chemistry, Univ of Pennsylvania
    • Department of Chemistry, University of Pennsylvania

  • Charles Kane

    • Univ of Pennsylvania
    • Department of Physics and Astronomy, University of Pennsylvania
    • Physics, University of Pennsylvania

  • Eugene Mele

    • Physics & Astronomy, University of Pennsylvania
    • Physics and Astronomy, University of Pennsylvania
    • Department of Physics and Astronomy, University of Pennsylvania
    • Univ of Pennsylvania
    • University of Pennsylvania

  • Ritesh Agarwal

    • Univ of Pennsylvania