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Tuning Chern Number in Quantum Anomalous Hall Insulators

ORAL

Abstract

The quantum anomalous Hall (QAH) effect is a two-dimensional topological insulating state that has quantized Hall resistance of h/Ce2 and vanishing longitudinal resistance under zero external magnetic field, where C is called Chern number. Up to now, the zero magnetic field QAH effect has been realized only for C = 1. Here we used molecular beam epitaxy to fabricate magnetic TI multilayers and realized the well-defined QAH effect with tunable Chern number up to 5. We further demonstrated that in the same multilayer configuration, the Chern number can be tuned by varying either the Cr doping level or the thickness of the interior magnetic TI layer. One theoretical model is developed to explain our experimental observations and establish the phase diagram for the QAH effect with the tunable Chern number. Our results facilitate the applications of dissipationless chiral edge currents in energy-efficient electronic devices and open the possibility for developing multi-channel quantum computing and high-capacity chiral circuit interconnects.

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Presenters

  • Yifan Zhao

    Pennsylvania State University, Department of Physics, Pennsylvania State University

Authors

  • Yifan Zhao

    Pennsylvania State University, Department of Physics, Pennsylvania State University

  • Ruoxi Zhang

    Pennsylvania State University

  • Ruobing Mei

    Pennsylvania State University

  • Ling-Jie Zhou

    Pennsylvania State University

  • Hemian Yi

    Pennsylvania State University, Department of Physics, Pennsylvania State University

  • Ya-Qi Zhang

    Pennsylvania State University

  • Jiabin Yu

    Pennsylvania State University, Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park

  • Run Xiao

    Pennsylvania State University, Physics, Pennsylvania State University

  • Ke Wang

    Pennsylvania State University, Materials Research Institute, The Pennsylvania State University

  • Nitin Samarth

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

  • Moses H W Chan

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

  • Chaoxing Liu

    The department of Physics, Pennsylvania State University, Pennsylvania State University, Department of Physics, the Pennsylvania State University, University Park

  • Cui-Zu Chang

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