Topological Hall Effect in Dual-gated Magnetic Topological Insulator Heterostructures

ORAL

Abstract

Magnetic chiral spin textures in real space serve as excellent model systems for fundamental studies of Berry curvature physics. The interaction of itinerant charge carriers with chiral spin textures induces an excess Hall voltage known as a ‘topological Hall (TH) effect,’ providing an indirect signature of non-trivial spin textures in transport measurements. Here, we report the observation of a possible TH effect in a heterostructure that sandwiches a topological insulator (TI) layer in between two magnetic TI layers. By varying the chemical potential using top and bottom gates, we map out the behavior of the TH effect and show that it is greatly enhanced when the chemical potential difference between the two surfaces is increased. This observation suggests that the excess Hall voltage is a result of a finite Dzyaloshinskii-Moriya interaction induced by the magnetization asymmetry in two magnetic layers. Apart from providing new insights into the TH effect, our study paves a new route for demonstrating proof-of-concept topological spintronic devices that rely on the interplay between momentum- and real- space spin textures.

*This work is supported by 2DCC-MIP (DMR-1539916), DOE (DE-SC0019064 and DE-SC0019331), ONR (N00014- 15-1-2370), and the Alfred P. Sloan Research Fellowship.

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Presenters

  • Run Xiao

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

Authors

  • Run Xiao

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

  • Jue Jiang

    • Physics, Penn State University

  • Morteza Kayyalha

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

  • Jae Ho Shin

    • Physics, Penn State University

  • Fei Wang

    • Physics, Penn 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

  • Jianxiao Zhang

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

  • Chaoxing Liu

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

  • Moses H W Chan

    • Physics, Penn 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

  • Nitin Samarth

    • Department of Physics and Materials Research Institute, Pennsylvania State University
    • Physics, Penn State University
    • Physics, The Pennsylvania State University
    • Pennsylvania State University
    • Department of Physics, Pennsylvania State University
    • Materials Research Institute, Pennsylvania State University
    • Department of Physics, The Pennsylvania State University
    • Physics, Pennsylvania State University