Revealing Hidden Phases in Correlated Electron Systems using Nonlinear Optics
15:30 - 16:30
Institute for Quantum Information and Matter, California Institute of Technology
CFEL (Bldg. 99)
Seminar Room IV, O1.111
James McIver / Andrea Cavalleri
The iridium oxide family of correlated electron systems is predicted to host a variety of exotic electronic phases owing to a unique interplay of strong electron-electron interactions and spin-orbit coupling. There is particular interest in the perovskite iridate Sr₂IrO₄ due to its striking structural and electronic similarities to the parent compound of high-Tc cuprates La₂CuO₄. Recent observations of Fermi arcs with a pseudogap behavior in doped Sr₂IrO₄ and the emergence of a d-wave gap at low temperatures further strengthen their phenomenological parallels.
In this talk I will describe our recently developed nonlinear optical spectroscopy and wide field microscopy techniques, which are highly sensitive to both the lattice and electronic symmetries of crystals. I will present results on the Sr₂IrO₄ system that reveal a subtle structural distortion and a hidden electronic phase that have previously eluded other experimental probes. I will comment on its relevance to the pseudogap region and also draw comparisons with our recent nonlinear optical data in the pseudogap region of the cuprates.