The electronic response of doped manganites at the transition from the paramagnetic insulating to the ferromagnetic metallic state in La1−xCaxMnO3 for (x=0.3,0.2) was investigated by dc conductivity, ellipsometry, and VUV reflectance for energies between 0 and 24 eV. A stablized Kramers-Kronig transformation yields the optical conductivity and reveals changes in the optical spectral weight up to 24 eV at the metal to insulator transition. In the observed energy range, the spectral weight is conserved within 0.3. The redistribution of spectral weight between low and high energies has important ramifications for the down-folding of low-energy Hamiltonians. We discuss the importance of the charge-transfer, Coulomb onsite, Jahn-Teller, and screening effects to the electronic structure.
@article{arxiv.cond-mat/0701348,
title = {Metal to insulator transition in manganites - optical conductivity changes up to 24 eV},
author = {A. Rusydi and R. Rauer and G. Neuber and M. Bastjan and I. Mahns and S. Müller and P. Saichu and B. Schulz and G. Stryganyuk and K. Dörr and G. A. Sawatzky and S. L. Cooper and M. Rübhausen},
journal= {arXiv preprint arXiv:cond-mat/0701348},
year = {2016}
}