Evidence for itineracy in the anticipated Kondo insulator FeSi: a quantitative determination of the band renormalization.

摘要: A comparison of high-resolution, angle-resolved photoemission spectroscopy (ARPES) data with ab initio band-structure calculations by density functional theory for the anticipated Kondo insulator FeSi shows that experimental dispersions can quantitatively be described an itinerant behavior provided appropriate self-energy correction is included, whose real part describes band renormalization due to interactions Fe 3d electrons. The imaginary self-energy, on other hand, determines linewidth quasiparticle peaks in ARPES data. We use a model which consistently both renormalized single-particle dispersion and energy-dependent bands. These results are clear evidence semiconductor properties explained without local Kondo-like interaction.