Predictive powers of the DFT+DMFT method for electronic and structural properties
· Invited
Abstract
Correlated materials are known to give rise to interesting physical properties such as superconductivity, colossal magnetoresistance, metal to insulator transitions, orbital and charge ordering, etc. In this talk I will present theoretical results for d- and f-systems, obtained with a method based on a combination of density functional theory (DFT) and dynamical mean field theory (DMFT). Due to recent development of forces for structural relaxations in DFT+DMFT method, we are now able to gain further insight into the couplings between electronic and structural degrees of freedom in the vicinity of a Mott transition, thus giving us predictive power for the electronic and structural properties of the correlated materials. Applying this method to AMnO3 (A=Bi,La) oxides, we find unusual electronic states with orbital selectivity, such as Site- and Orbital-Selective Mott state or Orbital-Selective Mott state. I will describe the electronic properties of such states and I will argue that: (1) these switchable novel states are a consequence of a highly sensitive interplay of the lattice with the electronic degrees of freedom of the correlated d-electrons and sp-electrons of the A ions; (2) based on the new understating of these electronic states we can explain the resonant x-ray scattering measurements, which till now could not be explained by other theoretical models. In addition, by comparing the DFT+DMFT structural relaxations at finite temperatures with the experimental crystal structures, we show that DFT+DMFT can capture the fine structural distortions induced by these unusual electronic states much better than DFT, thus confirming the predictive power of the DFT+DMFT method. I will end my talk discussing theoretical correlated electronic structure of filled skutterudites RPt4Ge12 (R=Ce,Pr) and comparison with experimental photoemission spectroscopy data.
*This work is supported by the U.S. Department of Energy as a part of the Computational Materials Science Program.
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Presenters
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G.L. Lucian Pascut
- Rutgers University, NJ, USA & “Stefan Cel Mare” University (USV), Suceava, Romania
- RCEM, Department of Physics and Astronomy, Rutgers U.
- Physics and Astronomy, Rutgers University, Piscataway, NJ, United States