Emergent helical edge states in a hybridized three-dimensional topological insulator

Abstract

As the thickness of a three-dimensional (3D) topological insulator (TI) becomes comparable to the penetration depth of surface states, hybridization turns their gapless Dirac electronic structure into a gapped spectrum. Here, authors show that 2D topological states can exist in the 3D TI BiSbTeSe2 when the Fermi level is inside the hybridization gap.