Center for Correlated Electron Systems

Seminar

Theoretical treatment of non-local correlations and screening within GW+DMFT: Distinguishing plasmon satellites from Hubbard bands in transition metal oxides

September 21, 2022l Hit 50
Date : September 28, 2022 10:30 ~ 12:00
Speaker : Prof. Steffen Backes (Ecole Polytechnique, University of Tokyo)
Location : Bldg. 19, Rm. 210

The high energy spectral features of strongly correlated materials so far have not received as much as attention as the low energy features. Well established is the picture of a correlated metal, which exhibits a renormalized quasi-particle peak at the Fermi level, with a transfer of spectral weight into upper and lower Hubbard bands that are separated by the low energy static value of the Coulomb interaction U . Recently, this picture has become blurred with the rise in interest in systems which show additional plasmonic satellites at higher energies as well as close to the Fermi level. This renders the theoretical identification of spectral features of correlated electron materials non-trivial, since plasmonic satellites are not captured by usual state-of-the-art dynamical mean-field theory (DMFT) calculations. I will present a theoretical approach of extending local many-body techniques such as DMFT to nonlocal correlations and interactions, which, in contrast to many existing approaches, preserves causality of the obtained spectral features. Using this method, I will show show how to distinguish plasmonic from Hubbard satellites within modern ab initio calculations. I will further present results for the transition metal oxides SrVO 3 and SrMoO 3 , which are found to exhibit both Hubbard and plasmonic satellites at very similar energetic positions.

 
Host : Dr. Choong Hyun Kim