Computing topological invariants without inversion symmetry

Article

关键词: SPACE GAUSSIAN PSEUDOPOTENTIALS;    HGTE QUANTUM-WELLS;    SINGLE DIRAC CONE;    WANNIER FUNCTIONS;    ENERGY-BANDS;    INSULATORS;    PHASE;    SURFACE;    SOLIDS;    BI2TE3;   

DOI  :  10.1103/PhysRevB.83.235401

来源: SCIE

【 摘 要 】

We consider the problem of calculating the weak and strong topological indices in noncentrosymmetric time-reversal (T) invariant insulators. In 2D we use a gauge corresponding to hybrid Wannier functions that are maximally localized in one dimension. Although this gauge is not smoothly defined on the two torus, it respects the T symmetry of the system and allows for a definition of the Z(2) invariant in terms of time-reversal polarization. In 3D we apply the 2D approach to T-invariant planes. We illustrate the method with first-principles calculations on GeTe and on HgTe under [001] and [111] strain. Our approach differs from ones used previously for noncentrosymmetric materials and should be easier to implement in ab initio code packages.

【 授权许可】

Free