Berry Phase Engineering in Magnetic Topological Insulator Heterostructures

ORAL

Abstract


The Berry phase, both in momentum-space and real-space, plays a key role in nontrivial transport phenomena such as the anomalous Hall (AH) and topological Hall (TH) effects. The AH effect is induced by Berry curvature in momentum space. The TH effect is a transport hallmark of chiral magnetic textures that are a consequence of Berry curvature in real space. In order to engineer the Berry phase, we have fabricated magnetic TI films and heterostructures and systematically studied their magneto-transport properties. We found that the sign of the AH effect in a magnetic TI film can be reversed through proximity to an undoped TI layer. By fabricating magnetic/nonmagnetic/magnetic TI sandwich heterostructures, we realized a square-shaped “hump” feature in the Hall traces, which is usually known as the TH effect. Combining transport measurements with magnetic force microscopy, we demonstrated that the TH effect-like “hump” feature observed here is not due to chiral magnetic textures but from the superposition of two AH effects with opposite signs. Our study provides a new route to engineer the Berry curvatures in magnetic TI heterostructures and facilitate the understanding of the interplay between the AH and TH effects.

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This work is supported by the ARO, DOE, and NSF 2DCC-MIP.

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Presenters

  • Fei Wang

    • Department of Physics, Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Department of Physics, The Pennsylvania State University

Authors

  • Fei Wang

    • Department of Physics, Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Department of Physics, The Pennsylvania State University

  • Yifan Zhao

    • Department of Physics, Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Pennsylvania State University

  • Di Xiao

    • Physics, Penn State University
    • Physics, The Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Wenbo Wang

    • Department of Physics and Astronomy, Rutgers University

  • Jue Jiang

    • Department of Physics, Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Pennsylvania State University

  • Ling Zhang

    • Physics, Penn State University
    • Department of Physics, Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Pennsylvania State University

  • Weiwei Zhao

    • School of Materials Science and Engineering, Harbin Institute of Technology
    • Department of Physics, Pennsylvania State University

  • Chao-Xing Liu

    • Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Department of Physics, Pennsylvania State University

  • Weida Wu

    • Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA
    • Department of Physics and Astronomy, Rutgers University
    • Physics and Astronomy, Rutgers University, New Brunswick
    • Rutgers University, New Brunswick

  • Moses H. W. Chan

    • Department of Physics, Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Pennsylvania State University

  • Nitin Samarth

    • Department of Physics, The Pennsylvania State University

  • Cui-Zu Chang

    • Pennsylvania State University
    • Physics, Penn State University
    • Department of Physics, Pennsylvania State University
    • Physics, The Pennsylvania State University
    • Department of Physics, The Pennsylvania State University