Ab-initio simulation of strongly correlated materials with large spin-orbit coupling
Gernot Kraberger
15:40 - 16:20 Friday 17 November 2017 Hörsaal Ventrex (NT03034)

In materials containing heavy transition metal atoms with open d-shells, electronic correlations and spin-orbit coupling (SOC) play an important role.
The interplay of these two ingredients can drastically alter the physics and give rise to interesting phenomena.
It is therefore desirable to develop a theoretical description of such systems that treats electronic correlations and SOC on equal footing.
A powerful way to account for the electron-electron interaction in crystals is the combination of density functional theory and dynamical mean-field theory (DFT+DMFT), which allows to study strongly correlated materials from first principles.
While SOC can be included on the level of DFT in many available computer codes, performing DMFT on top of such a DFT+SOC calculation is not straightforward.

In this talk, I will first give an introduction to the principles of ab-initio simulations, present the strongly correlated regime of interacting electrons and discuss the origin and consequences of the SOC.
Then, a focus is put on the DFT+DMFT and the necessary adaptations of that standard framework to overcome the challenges one faces when SOC needs to be included.
Finally, the interplay of electronic correlations and SOC in a real material is illustrated on the example of the double perovskite Sr$_2$MgOsO$_6$, where both ingredients show a strong influence on the electronic structure.