Abstract of the talk
The Iridate compounds are ideal playgrounds to investigate nontrivial correlation effects in topological transitions. The iridium 5d electrons have comparable strength of spin-orbit coupling and local Coulomb interactions: competition between various energy scales in iridate compounds leads to a rich phase diagram, including topological Weyl semimetals. In this talk, I discuss the role of interactions in the topological phase transitions, focussing on pyrochlore iridates (R2Ir2O7, where R is a rare earth) case. The system shows metal insulator transitions as the interaction strength increases, with an intermediate topological semimetallic phase. The non-perturbative effects are captured by dynamical mean-field theory (DMFT), which has shown its power to study strongly correlated systems. By embedding a quantum impurity (or a cluster) into self-consistently obtained effective bath, the DMFT describes local quantum fluctuations beyond the mean-field level. Since the spatial correlation turned out to be essential to the Weyl semimetallic phase, I also provide a brief overview of technical aspects of the DMFT, current status and outlook.
Biography of the Speaker
Dr. Ara Go is currently a Junior Research Team Leader at IBS Center for Theoretical Physics of Complex Systems (PCS). She received her B.S. degree from Seoul National University in 2005 and Ph.D. in 2012. She then worked at Columbia University as a postdoctoral researcher from 2012 until she joined Institute for Basic Science in 2016. Dr. Ara Go’s research interest include development of numerical algorithms to study correlated electronic systems, correlation effects in materials with strong spin-orbit coupling, computational study on spectral properties in strongly correlated systems, quantum embedding theories, and dynamical mean-field theory and impurity solvers.