Seminarium Fizyki Materii Skondensowanej

I will discuss current theoretical challenges in the study of solid state materials and I will describe my group's contributions to the development of post-DFT methods in the weakly correlated regime. In the first part of my talk, I will present a formulation of relativistic self-consistent GW for solids based on the exact two-component formalism with one-electron approximation (X2C1e) and non-relativistic Coulomb interactions. This theory allows us to study scalar relativistic effects, spin-orbit coupling, and the interplay of relativistic effects with electron correlation without adjustable parameters. In the second part, I will talk about the applications of this method to (i) evaluating Neel temperatures of transition metal oxides, (ii) analyzing topological effects in candidates for topological insulators, (iii) finding multiple solutions corresponding to different phases. Finally, I will discuss challenges and future developments in making the ab-initio post-DFT methods systematically improvable, predictive, controlled, and widely applied to many classes of problems.