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Condensed Matter Physics Seminar

Condensed Matter Physics Seminar


Proximity of Iridates to correlated topological phases and non-fermi liquid phases in nickelates


Dr. Mehdi Kargarian

The University of Texas at Austin and The Ohio State University


This talk is mainly about oxides: Iridates and Nicklates. In first part I talk on proximity of iridates to topological insulator phases, which are gapped in bulk spectrum but still possess metallic surface states protected by time reversal symmetry. The driving force for band inversion is strong spin-orbit coupling. While the noninteracting picture of TIs and their classification have been very well understood, the effects of Coulomb interactions on TIs and searching for new candidates hosting these phases need to be understood better. Iridium-based materials or iridates, transition metal oxides with 5d elements, are good candidates, because they have strong SOC and are weakly correlated. However, the SOC amplifies the Coulomb interaction giving rise to novel Mott insulators. I will address the effects of correlations on topological insulator phases in iridates in 2D and 3D. In particular, I will discuss how the SOC affects the magnetic phases emerged at strong interacting limit. I will also discuss that the ground states of some iridates with pyrochlore lattice could be topological crystalline insulators as long as mirror symmetry is preserved. In second part, if time permits, I will discuss the non-fermi liquid phase in another class of oxides, the Nickelates.


Sunday 29th December (8th DEY), 3:00 PM


Physics Auditorium, Physics Department Basement