The pressure effects on electronic structure of iron chalcogenide superconductors FeSe1-xTex

Abstract

We study the electronic structure of iron-based superconductors FeSe 1-xTex within the density functional theory. We pay particular attention to the pressure effects on the Fermi surface (FS) topology, which seem to be correlated with a critical superconducting temperature TC of iron chalcogenides and pnictides. A reduction of the FS nesting between hole and electron cylinders with increasing pressure is observed, which can lead to higher values of TC. The tellurium substitution into selenium sites yields FS changes similar to the pressure effect.