Dirac Band Engineering of Topological Insulator/Graphene Hybrid Structures

ORAL

Abstract

Dirac materials such as graphene and topological insulators (TI) have attracted much attention because of their unique electrical properties. Stacking these two Dirac materials to form a heterostructure provides a platform for the exploration of the interesting physics of coupled Dirac fermions. We recently used molecular beam epitaxy to fabricate the (Bi1-xSbx)2Te3/graphene hybrid structures and systematically studied the electronic band structures as a function of x and thickness. Because the ratio between the lattice constants of Sb2Te3 and graphene is √3, the Dirac cone of graphene can be folded to the Γ point of the Brillouin zone of Sb2Te3. The coexistence of two different Dirac low-energy states is indeed observed in angle-resolved photoemission spectroscopy measurements. This phenomenon is further demonstrated by scanning tunneling microscopy results and first-principles calculations. Our work is of great importance for understanding the interplay of Dirac fermions across the TI/graphene interface and paves a new way to study band engineering in Dirac materials.

*This work is supported by the NSF-CAREER award (DMR-1847811) and NSF-2DCC-MIP (DMR-1539916).

–

Presenters

  • Guang Wang

    • Pennsylvania State University
    • Department of Physics, National University of Defense Technology
    • Department of Physics, Pennsylvania State University

Authors

  • Guang Wang

    • Pennsylvania State University
    • Department of Physics, National University of Defense Technology
    • Department of Physics, Pennsylvania State University

  • Yifan Zhao

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

  • Huixia Fu

    • Weizmann Institute of Science
    • Department of Condensed Matter Physics, Weizmann Institute of Science
    • Condensed Matter Physics, Weizmann Insitute of Science
    • Physics, Chinese Academy of Sciences

  • Zengle Huang

    • Department of Physics and Astronomy, Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University

  • Fei Wang

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

  • Hemian Yi

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

  • Timothy Pillsbury

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

  • lingjie zhou

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

  • Chengye Dong

    • Pennsylvania State University
    • Department of Materials Science and Engineering, The Pennsylvania State University

  • Joshua Robinson

    • Pennsylvania State University
    • Department of Materials Science and Engineering, The Pennsylvania State University
    • Department of Materials Science and Engineering, Pennsylvania State University

  • Nitin Samarth

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

  • Weida Wu

    • Physics and Astronomy, Rutgers University, New Brunswick
    • Department of Physics and Astronomy, Rutgers University
    • Department of Physics and Astronomy, Rutgers, The State University of New Jersey
    • Department of Physics and Astronomy, Rutgers University, New Brunswick
    • Rutgers University, New Brunswick

  • binghai yan

    • Department of Condensed Matter Physics, Weizmann Institute of Science
    • Weizmann Institute of Science
    • Weizmann institute of science

  • Cui-Zu Chang

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