Special seminars TRR80

11.10.2018 4:15 p.m., room: S-288
Prof. Dr. Hiroshi Yasuoka (Max-Planck-Institut für chemische Physik fester Stoffe, Dresden)
Weyl fermion excitations in transition metal pnictides explored by 93Nb NMR and 181Ta NQR
30.10.2018 4 p.m., room: S-288
Prof. Dr. Markus J. Aichhorn (TU Graz)
Strong Correlations and Spin-Orbit Coupling: Models and Materials

Strong electron correlations appear when the kinetic energy in a system is comparable or smaller than the repulsive Coulomb interaction energies. Until a few years ago this behavior was attribute in transition metal compounds almost exclusively to materials with open 3d shells, and just a few studies on a limited amount of systems have been done outside of this play ground. Only recently, it has been noted that also systems with 4d or even 5d electronic states in the conduction bands can show very interesting and unexpected behavior. A prime example are strontium iridates and rhodates, where the first one is a spin-orbit assisted insulator, whereas the latter one stays metallic.

Motivated by these interesting materials, we will first study the interplay of spin-orbit coupling and electronic correlations on a general model level. Applying continuous time quantum Monte Carlo methods to a three band model on the Bethe lattice, we see that the importance of spin-orbit coupling for electronic correlations strongly depends on other system paramaters, with the electron density the most important one.

Second, we will relate these findings to real materials. We will discuss their relevance to strontium iridates and rhodates, as well as some osmium double perovskites. We will show that spin-orbital polarisation is indeed a prime factor for the understanding of these materials' properties.

17.1.2019 2:30 p.m., room: S-403
Prof. Dr. Sándor Bordács (BUTE, Budapest)
Detection of antiferromagnetic domains by optical magnetoelectric effect
29.1.2019 4 p.m., room: S-288
Dr. Maia G. Vergniory (Donostia International Physics Center, Ikerbasque)
Higher Order Topological Insulators from Elementary Band Representations Theory
22.2.2019 10:30 a.m., room: S-288
Prof. Dr. Andrei Pimenov (Institut für Festkörperphysik, TU Wien)
Topological insulators: quantized Faraday rotation and the band structure
19.3.2019 4 p.m., room: S-403
Prof. Dr. Sergey Artyukhin (Italian Institute of Technology (IIT), Genoa)
Sliding domain walls in ferroelectrics and multiferroics
22.3.2019 2 p.m., room: S-288
Dr. F. Sebastián Bergeret (Materials Physics Center, CSIC, Spain)
Universal correspondence between edge spin accumulation and equilibrium spin-currents in nanowires