Doping Induced Spin State Transition in LaCoO3: Dynamical Mean-Field Study

TL;DR

This study uses dynamical mean-field theory to analyze doping effects in LaCoO3, revealing that the intermediate spin state is not crucial for susceptibility and showing the importance of t2g bands crossing the Fermi level.

Contribution

It provides a novel dynamical mean-field analysis of doped LaCoO3, challenging previous assumptions about spin states and electron roles.

Findings

Atomic intermediate spin state is not key for Curie-Weiss susceptibility.

Narrow t2g quasiparticle bands cross the Fermi level.

Strongly damped eg excitations observed.

Abstract

Hole and electron doped LaCoO3 is studied using dynamical mean-field theory. The one-particle spectra are analyzed and compared to the available experimental data, in particular the x-ray absorption spectra. Analyzing the temporal spin-spin correlation functions we find the atomic intermediate spin state is not important for the observed Curie-Weiss susceptibility. Contrary to the commonly held view about the roles played by the t2g and eg electrons we find narrow quasiparticle bands of t2g character crossing the Fermi level accompanied by strongly damped eg excitations.