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PGI-1 Seminar: Dr. Hongbin Zhang

Effective J=1/2 insulating state in Ruddlesden-Popper iridates: An LDA+DMFT study

13.Nov.2013 11:30

Rudgers University, New Jeresy, USA


The competition between spin-orbit coupling and electron correlations in 5d compounds gives rise to many interesting phenomena. One particularly
attractive case is the eective J = 1=2 insulating phase found in the rst member of Ruddlesden-Popper (RP) iridates Sr2IrO4.1 Using ab-initio methods, we2 investigate the metal-insulator transition across the RP iridates and explore the robustness of the eective J =1=2 state against band eects due to itineracy, tetragonal distortion, octahedral rotation and Coulomb interaction. The electronic structures we obtained are in good agreement with recent ARPES measurements.3;4;5 We predict the eects of epitaxial strain on the optical conductivity, magnetic moments and eective J =1=2 groundstate wave functions in the RP series. We demonstrate that the deviation from the ideal eective J =1=2 state is negligible at short time scales for both Sr2IrO4 and Sr3Ir2O7, while it becomes quite signicant for Sr3Ir2O7 at long times and low energy, leading to a reconciliation of previous contradictory experimental results.


Prof. Dr. Stefan Blügel
Phone: +49 2461 61-4249
Fax: +49 2461 61-2850
email: s.bluegel@fz-juelich.de