Topological phase transition in compressed van der Waals superlattice heterostructure BiTeCl/HfTe₂

Abstract

Based on first-principles calculation, we investigate electronic band structures and topological properties of heterostructure BiTeCl/HfTe2 under c direction strain. In the primitive structure, this material undergoes phase transition from insulator with narrow indirect gap to metal by strong spin-orbital coupling. When strain effect is considered, band inversion at time-reversal invariant point Z is responsible for topological phase transition. These nontrivial topologies are caused by two different types of band crossing. The observable topological surface states in (110) surface also support that this material experiences topological phase transition twice. The layered heterostructure with van der Waals force provides us a new desirable platform to control topological phase transition and construct topological superconductors.