Chemical Bonding Induced Topological Lifshitz Transition in Type-II Dirac Semimetal VAl3

ORAL

Abstract

We report a chemical bonding induced Lifshitz transition of Ti1-xVxAl3 in which the compounds evolve from p-type trivial metal to n-type robust Dirac semimetal. This topological transition is concomitant with an anomalous structural distortion which stems from the interplanar V-Al bond formation. The V-Al bonds in Ti1-xVxAl3 are built up as long as the bonding orbitals of V atoms are fully populated by the electrons. In other words, the type-II Dirac semimetal state of VAl3 is protected by the V-Al bonds whose molecular orbitals are the “gravity center” of the topological electron and hole bands.

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Presenters

  • Shuang Jia

    International Center for Quantum Materials, Peking University, Peking University, China, Physics, Peking University, Peking University, International Center for Quantum Materials, School of Physics, Peking University

Authors

  • Yi-Yuan Liu

    Physics, Peking University

  • Yu-Fei Liu

    Physics, Peking University

  • Xin Gui

    Chemistry, Louisiana State University, Louisiana State University, Department of Chemistry, Louisiana State University, Chemistry, Louisiana State Univeristy

  • Cheng Xiang

    Physics, Peking University

  • Huibing Zhou

    Physics, Peking University, International Center for Quantum Materials, Peking University

  • Weiwei Xie

    Chemistry, Louisiana State University, Louisiana State University, Department of Chemistry, Louisiana State University, Chemistry, Louisiana State Univeristy

  • Chuang-Han Hsu

    Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, National University of Singapore, Physics, National University of Singapore

  • Hsin Lin

    Academia Sinica, Institute of Physics, Academia Sinica, Physics, Academia Sinica, Taipei 11529, Taiwan, Institute of Physics, Academia Sinica, Taipei 11529, Taiwan, Physics, Academia Sinica, Department of Physics, National University of Singapore, National University of Singapore, Academia Sinica, Taipei, Taiwan

  • Tay-Rong Chang

    National Cheng Kung University, Physics, National Cheng Chung University, Physics, National Cheng Kung University, Tainan, 701, Taiwan, Department of Physics, National Cheng Kung University, Physics, National Tsing Hua University, Physics, National Cheng Kung University

  • Shuang Jia

    International Center for Quantum Materials, Peking University, Peking University, China, Physics, Peking University, Peking University, International Center for Quantum Materials, School of Physics, Peking University