DFT+DMFT for spin-orbit coupled systems: implementation and application to an oxide heterostructure

Gernot Kraberger (Speaker)

Activity: Talk or presentationPoster presentationScience to science

Description

In systems containing heavy atoms with open d-shells, both electronic correlations and spin-orbit coupling (SOC) play an important role. Therefore, both have to be included in a theoretical description of such materials. A very successful way to account for the electron-electron interaction in crystals is the DFT+DMFT. In this contribution, we explain a strategy to tackle all the obstacles one faces when including SOC in this well-established framework.
Typically, SOC leads to significant complex-valued orbital hybridisations that are absent otherwise. As a consequence one has to deal with matrix valued Green's functions, which causes difficulties for the Monte-Carlo impurity solvers, mainly by a pronounced fermionic sign problem. We show that a carefully chosen basis rotation can drastically improve this issue. But still, the numerical effort increases significantly when accounting for SOC, as the number of internal symmetries is reduced. We present our approach to reduce the degrees of freedom to make prohibitively costly calculations feasible. All these points are illustrated with the layered oxide heterostructure SrTiO3/SrIrO3 as example system.
Period18 Jul 2017
Event titleSCES 2017
Event typeConference
Location
Degree of RecognitionInternational

ASJC Scopus subject areas

  • Condensed Matter Physics