Investigation of correlation effects in FeSe and FeTe by LDA + U method

• Comparative study of the influence of U and J in FeSe and FeTe.
• We found correlation effects are strong in Fe-3d orbitals in FeSe and FeTe.
• Correlation effects are orbital selective in nature.

We present a comparative study of the influence of Coulomb interaction and Hund’s coupling on the electronic structure of FeSe and FeTe. Our calculations are based on density functional theory (DFT) with local density approximation (LDA + U) framework employed in TB-LMTO ASA code. We found the correlation effects are orbital selective due to the strength of interorbital hybridization among the different Fe-3d orbitals mediated via the chalcogen (Se/Te-p) orbitals and are different in both the compounds. The Coulomb interaction is screened significantly by Te-p bands in FeTe. Similarly the orbital selection is different in both the compounds because of the difference in the chalcogen height.