Suppression of electronic correlations by chemical pressure from FeSe to FeS

Abstract

In iron-based superconductors, the interplay between nematicity, magnetism, and superconductivity is still not fully understood. Experimentally, the isoelectronic series FeSe${}_{1-x}$S${}_{x}$ provides an ideal playground to tune different electronic ground states and to selectively investigate their mutual interplay. Here, the authors use high-resolution angle-resolved photoemission spectroscopy to compare the electronic structure of different single crystals in the tetragonal phase. They find that in the absence of nematicity and magnetism, the substantial reduction of electronic correlations correlates with the decrease of the superconducting transition temperature from FeSe to FeS.