Asymmetric mass acquisition in LaBi: Topological semimetal candidate

Article

关键词: TOTAL-ENERGY CALCULATIONS;    WEYL FERMION SEMIMETAL;    HGTE QUANTUM-WELLS;    SINGLE DIRAC CONE;    WAVE BASIS-SET;    INSULATOR;    SURFACE;    ARCS;    DISCOVERY;    PHASE;   

DOI  :  10.1103/PhysRevB.94.081108

来源: SCIE

【 摘 要 】

We use our high resolution He-lamp-based, tunable laser-based angle-resolved photoemission spectroscopy measurements and density functional theory calculations to study the electronic properties of LaBi, a binary system that was proposed to be a member of a new family of topological semimetals. Both bulk and surface bands are present in the spectra. The dispersion of the surface state is highly unusual. It resembles a Dirac cone, but upon closer inspection we can clearly detect an energy gap. The bottom band follows roughly a parabolic dispersion. The dispersion of the top band remains very linear, V -shape like, with the tip approaching very closely to the extrapolated location of Dirac point. Such asymmetric mass acquisition is highly unusual and opens a possibility of a new topological phenomenon that has yet to be understood.

【 授权许可】

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