Emergence of orbital-selective marginal Fermi liquidness in compressed RbFe2Te3

Abstract

Driving a Mott insulator towards an orbital-selective metal with coexisting Mott localized and marginal Fermi liquid electronic states remains central to understanding various correlated emergent phenomena. Here, using density functional dynamical mean-field theory we explore correlation and hole-doping-induced electronic reconstruction in ${\mathrm{RbFe}}_{2}{\mathrm{Te}}_{3}$, a potential two-leg ladder system for hole carrier superconductivity under pressure. We stress the importance of multiorbital Coulomb interactions in concert with band structure calculations for a consistent understanding of intrinsic Mott localization at ambient pressure. We elucidate the nature of pressure-induced Mottness upon tuning the correlation to bandwidth ratio away from the Mott boundary. As a by-product of our analysis, a quantum critical phenomenon with coexisting Mott localized and marginal Fermi liquid electrons is predicted to exist in compressed ${\mathrm{RbFe}}_{2}{\mathrm{Te}}_{3}$ metal.