University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Thursday, April 16th 2015
1:15 pm:
Condensed Matter Seminar in 210 Physics
Speaker: David Hsieh, Institute for Quantum Information and Matter, CIT
Subject: Subtle structural distortions and a hidden magnetic phase in Sr2IrO4 revealed using nonlinear optical measurements
Please note: change of time for seminar, in effect for rest of semester.

Iridium oxides are predicted to host a variety of exotic electronic phases emerging from the interplay of strong electron correlations and spin-orbit coupling. There is particular interest in the perovskite iridate Sr2IrO4 owing to its striking structural and electronic similarities to the parent compound of high-Tc cuprates La2CuO4. However, despite theoretical predictions for unconventional superconductivity and recent observations of Fermi arcs with a pseudogap behavior in doped Sr2IrO4, no superconductivity has been observed in this compound so far. In this talk I will describe the nonlinear optical spectroscopy and wide field microscopy techniques that we have recently developed to resolve the symmetries of both lattice and electronic multipolar ordered phases on single domain length scales. I will show our results on the undoped Mott insulator Sr2IrO4 that reveal a subtle structural distortion and provide evidence for a hidden loop-current ordered magnetic phase that has previously eluded other experimental probes. The significance of these novel orders to magneto-elastic coupling and the pseudogap phase in Sr2IrO4 will be discussed.

Faculty Host: Natalia Perkins

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