Novel family of chiral-based topological insulators: Elemental tellurium under strain
Luis A. Agapito, Nicholas Kioussis, William A. Goddard III, and N. P. Ong
Accepted
Employing ab initio electronic structure calculations we predict, that trigonal tellurium consisting of weakly interacting helical chains, undergoes a trivial insulator to strong topological insulator (metal) transition under shear (hydrostatic or uniaxial) strain. The transition is demonstrated by examining the strain evolution of the band structure, of the topological \mathbbZ2 invariant, and the concomitant band inversion. The underlying mechanism is the depopulation of the lone-pair orbitals, associated with the valence band, via proper strain engineering. Thus, Te becomes the prototype of a novel family of chiral-based 3D TIs with important implications in spintronics, magneto-optics and thermo-electrics.