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.

The calculated Fermi surface sheets of tensile strained FeTe.Figure optionsDownload as PowerPoint slide