Realization of Weyl semimetal phase in a non-centrosymmetric superlattice in Kane-Mele mode

Abstract

We investigate a superlattice alternately composed of quantum spin Hall insulators in Kane-Mele model and two-dimensional normal insulators due to the staggered lattice potential. The staggered lattice potential in normal insulators as a spacer layer has a role of breaking an inversion symmetry in current study. We show a realization of Weyl semimetal (WSM) phase in a finite region and a phase transition to a weak topological insulator. We estimate Z(2) topological invariants by means of Wannier charge center method which is practical for non-centrosymmetric topological insulators. We also discuss Fermi arcs and chiral charges of WSM phase in surface Brillouin zone.