Importance of long-range correlations in transition metal compounds: First-principle studies using the the multitier GW+EDMFT approach

Transition metal compounds exhibit a wide range of intriguing properties, such as high temperature superconductivity and colossal magnetoresistance. The standard method to describe these materials is density functional theory + dynamical mean-field theory (DFT+DMFT), which can treat the strong onsite correlations between the 3d electrons to all orders but omits the long-range intersite correlations. In this talk I discuss the recently developed multitier combination of the GW-approximation and dynamical mean-field theory [1], a parameter-free ab-initio method which yields a fully self-consistent description of both long- and short-range correlations. A systematic study of the cubic perovskites Sr(V,Mo,Mn)O3 reveal that the long-range correlations, which are typically ignored for this class of materials, can have a profound influence on the interpretation of the spectra. Specifically spectral features previously interpreted as Hubbard bands are reinterpreted as plasmon satellites originating from long-range charge fluctuations.
[1] L. Boehnke et al PRB 94 2016, F. Nilsson et. al PRM 1 2017