Superconductivity and Jahn Teller effect in iron pnictide superconductors

Abstract

Though 100 years old, superconductivity is still one of the most active fields in con- newlinedensed matter physics. The discovery of new superconductors attracts always great newlineattention. Especially the high temperature superconductors such as the cuprate and newlineiron-based superconductors put the superconductivity research in the forefront of newlinecondensed matter physics. newlineHosono et al.[1] initiated the study of iron-based superconductors in 2006, and newlinethe subject came to the forefront in 2008 after the discovery of LaFeAsO1and#8722;xFx with newlineTc and#8771; 26K. Since then, an enormous amount of research has been done on this new newlineever growing family, with Tc reaching temperatures as high as 55K. Up to now, newlines±-wave, an extended s-wave pairing with opposite signs of the order parameters newlinebetween the hole pockets and the electron pockets mediated by magnetic excitations, newlineis a strong candidate for the gap symmetry in iron-based superconductors. newlineIn the present work the microscopic theoretical studies are presented t newline