Topological phase transition and two-dimensional topological insulators in Ge-based thin films

Article

关键词: QUANTUM SPIN HALL;    T-MATRIX APPROXIMATIONS;    MUFFIN-TIN ALLOYS;    SINGLE DIRAC CONE;    TERNARY COMPOUNDS;    EFFICIENT;    BI2SE3;    STATES;   

DOI  :  10.1103/PhysRevB.88.195147

来源: SCIE

【 摘 要 】

We discuss possible topological phase transitions in Ge-based thin films of Ge(BixSb1-x)(2)Te-4 as a function of layer thickness and Bi concentration x using the first-principles density functional theory framework. The bulk material is a topological insulator at x = 1.0 with a single Dirac cone surface state at the surface Brillouin zone center, whereas it is a trivial insulator at x = 0. Through a systematic examination of the band topologies, we predict that thin films of Ge(BixSb1-x)(2)Te-4 with x = 0.6, 0.8, and 1.0 are candidates for two-dimensional (2D) topological insulators, which would undergo a 2D topological phase transition as a function of x. A topological phase diagram for Ge(BixSb1-x)(2)Te-4 thin films is presented to help guide their experimental exploration.

【 授权许可】

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