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