Optical Evidence of Chiral Magnetic Anomaly in Weyl Semimetal TaAs

ORAL

Abstract

Chiral pumping from optical electric fields oscillating at THz frequencies is observed in the Weyl material TaAs with electric and magnetic fields aligned along both the a- and c-axes. Free carrier spectral weight enhancement is measured directly for the first time, confirming theoretical expectations of chiral pumping. A departure from linear field-dependence of the Drude weight is observed at the highest fields in the quantum limit, providing direct evidence of field-dependent Fermi velocity of the chiral Landau level. Implications for the chiral magnetic effect in Weyl semimetals from the optical f-sum rule are discussed

*Work at UCLA was supported by the U.S. Department of Energy (DOE) under Award Number de-sc0011978. A.B. Sushkov and H.D.Drew were supported by DOE desc0005436 grant, A.L. Levy, G.S. Jenkins and H.D.Drew were supported by NSF DMR-1610554. F. Liu was supported by China Scholarship Council No. 201508340005.

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Presenters

  • Antonio Levy

    • Department of Physics, Center for Nanophysics and Advanced Materials, University of Maryland

Authors

  • Antonio Levy

    • Department of Physics, Center for Nanophysics and Advanced Materials, University of Maryland

  • Andrei B Sushkov

    • Department of Physics, Center for Nanophysics and Advanced Materials, University of Maryland

  • Fengguang Liu

    • Anhui Agricultural University

  • Bing Shen

    • Department of Physics and Astronomy, University of California, Los Angeles
    • University of California, Los Angeles
    • Physics and Astronomy, university of california los angeles

  • Ni Ni

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

  • Howard Drew

    • Department of Physics, Center for Nanophysics and Advanced Materials, University of Maryland

  • Gregory S Jenkins

    • Laboratory for Physical Sciences