Orbital-selective nature of the 3d electronic structure of the ThFeAsN superconductor

Abstract

Based on local-density approximation plus dynamical mean-field theory ($\mathrm{LDA}+\mathrm{DMFT}$) calculations, we perform a comprehensive analysis of electronic structure reconstruction of the ThFeAsN superconductor, showing how the normal and $s$ wave superconducting spectra are reshaped by many-particle electron-electron interactions. Here, the ThFeAsN parent compound is described as an orbital-selective marginal Fermi liquid metal, with coexisting Fermi liquid quasiparticles and pseudogapped electronic states. Upon electron doping, an additional Kondo insulating state is predicted to exist in this system. Furthermore, we show how dynamical correlations strongly renormalize the bare Bogoliubov quasiparticles in the $s$ wave superconducting state into totally correlated lineshapes. These findings contribute to the microscopic understanding of the role played by dynamical multiorbital electronic correlations in the low energy spectrum relevant to unconventional Fe-based superconductors.