Strain effects on electronic structure and superconductivity in the iron telluride

•Influence of tensile strain on crystal and electronic structures of FeTe studied ab initio.•The superconducting tensile-strained FeTe exhibits specific Fermi surface (FS) nesting.•The FS nesting is analogous to that in superconducting FeSe at ambient pressure.•Similar mechanisms of superconductivity possible in both the compounds.

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) × (2π/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 transition from the double-stripe to the single-stripe magnetic order in FeTe under tensile strain in the ab-plane is associated with an occurrence of superconductivity in corresponding thin films, these findings allow for drawing a consistent picture of superconductivity in FeSe1−xTex systems, in general.

Graphical abstractThe calculated Fermi surface sheets of tensile strained FeTe.Figure optionsDownload full-size imageDownload as PowerPoint slide