Strain effects on electronic structure and superconductivity in the iron telluride

The influence of tensile strain in the ab-plane on crystal and electronic structure of FeTe has been studied ab initio. In superconducting FeSe the Fermi surface nesting with a vector q~(0.5,0.5)(2\pi /a) is believed to be crucial for rising superconductivity mediated by spin-fluctuations. The results presented here indicate that tensile-strained FeTe also exhibits such conditions. Furthermore, the Fermi surface changes, related to the increase of the lattice parameter a of this telluride, are opposite to analogous effects reported for FeSe. Since a recently reported transition from the double-stripe to the single-stripe magnetic order in FeTe under tensile strain in the ab-plane is associated with an occurence of superconductivity in corresponding thin films, these findings allow for drawing a consistent picture of superconductivity in FeSe(1-x)Te(x) systems, in general.