Topological semimetal to insulator quantum phase transition in the Zintl compounds Ba2X(X = Si,Ge)

Article

关键词: TOTAL-ENERGY CALCULATIONS;    WEYL FERMION SEMIMETAL;    MOLECULAR-DYNAMICS;    DIRAC SEMIMETAL;    METALS;    DISCOVERY;    SURFACE;    WELLS;    ARCS;   

DOI  :  10.1103/PhysRevB.94.155121

来源: SCIE

【 摘 要 】

By first-principles calculations, we find that Ba2X(X = Si, Ge) hosts a topological semimetal phase with one nodal ring in the k(x) = 0 plane, which is protected by the glide mirror symmetry when spin-orbit coupling (SOC) is ignored. The corresponding drumheadlike surface flat band appears on the (100) surface in surface Green's function calculation. Furthermore, a topological-semimetal-to-insulator transition is found. The nodal line semimetal would evolve into a topological insulator as SOC is turned on. The topologically protected metallic surface states emerge around the (Gamma) over bar point, which could be tuned into the topologically trivial insulator state by more than 3% hydrostatic strain. These results reveal a category of materials showing quantum phase transition between topological semimetal and insulator, and tunability through elastic strain engineering.

【 授权许可】

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