The influence of various strains on crystal and electronic structures of superconducting FeSe has been studied ab initio. We consider changes in the Fermi surface nesting with a vector Q=(0.5,0.5)*(2\pi /a) as crucial for rising superconductivity (SC) mediated by spin-fluctuations (SF). Our results indicate that the c-axis strained FeSe exhibits the most imperfect nesting, which enhances SF and, hence, also SC. In turn, the ab-plane compressive strain slightly weakens this} nesting while the tensile strain destroys it completely. These findings are consistent with reported earlier experimental dependencies of superconducting transition temperatures on strain in FeSe thin films.
@article{arxiv.1308.2933,
title = {Strain effects on electronic structure of the iron selenide superconductor},
author = {M. J. Winiarski and M. Samsel-Czekała and A. Ciechan},
journal= {arXiv preprint arXiv:1308.2933},
year = {2016}
}