Center for Correlated Electron Systems


Raman scattering studies on Sr2IrO4 thin films under epitaxial stress and strain

June 3, 2019l Hit 424
Date : June 14, 2019 16:00 ~ 17:30
Speaker : Prof. Ambrose Seo(University of Kentucky)
Location : Bldg. 19, Rm. 210

Scattering experiments are essential to understand intriguing phenomena in many areas of physics.  For example, recent advance of experimental methods such as inelastic neutron scattering and resonant inelastic x-ray scattering plays an important role in condensed matter physics.  In particular, inelastic scattering can detect various low energy excitations in condensed matter.  However, while research on epitaxial thin-films is expected to reveal hidden novel physical properties, previous experiments such as inelastic neutron scattering have been unsuccessful due to small cross-section.

In this seminar, I will discuss advanced inelastic light (Raman) scattering studies of two-magnon dynamics in Sr 2 IrO 4 epitaxial thin-films as functions of epitaxial stress and temperature.  Recent experimental studies of Sr 2 IrO 4 thin-films have contradicted the widely-accepted Glazer description of octahedral tilting and rotation in perovskite oxides.  However, our experimental observations and density functional theory calculations show that the multi-orbital nature of the J eff = ½ state is crucial to understanding the magnetic and electronic properties of 5 d transition-metal oxides.  This study demonstrates how advanced scattering tools combined with epitaxially stressed samples can improve our fundamental understanding of strongly correlated, spin-orbit coupled electrons, enabling us to explore the novel phase diagrams of these systems.


Host: Prof. Tae Won Noh