# Importance of conduction electron correlation in a Kondo lattice, Ce2CoSi3 - Condensed Matter > Strongly Correlated Electrons

Abstract: Kondo systems are usually described by the interaction of strong correlationinduced local moment with the highly itinerant conduction electrons. Here, westudy the role of electron correlations among conduction electrons in theelectronic structure of a Kondo lattice compound, Ce$2$CoSi$3$, using highresolution photoemission spectroscopy and {\it ab initio} band structurecalculations, where Co 3$d$ electrons contribute in the conduction band. Highenergy resolution employed in the measurements helped to reveal signature of Ce4$f$ states derived Kondo resonance feature at the Fermi level and dominance ofCo 3$d$ contributions at higher binding energies in the conduction band. Theline shape of the experimental Co 3$d$ band is found to be significantlydifferent from that obtained from the band structure calculations within thelocal density approximations, LDA. Consideration of electron-electron Coulombrepulsion, $U$ among Co 3$d$ electrons within the LDA+$U$ method leads to abetter representation of experimental results. Signature of electroncorrelation induced satellite feature is also observed in the Co 2$p$ corelevel spectrum. These results clearly demonstrate the importance of theelectron correlation among conduction electrons in deriving the microscopicdescription of such Kondo systems.

Author: Swapnil Patil, Sudhir Pandey, V. R. R. Medicherla, R. S. Singh, R. Bindu, E. V. Sampathkumaran, Kalobaran Maiti

Source: https://arxiv.org/