Jun-Sik Lee Seminar
One of the most challenging extant issues in condensed matter physics and applied materials science is the search for post-silicon based electronics, and multi-functional complex oxides offer hopes that new classes of devices can be developed out of these intriguing materials. In that context, the strongly correlated systems display an extremely rich interplay of charge, spin, and lattice interactions that have extensively been studied. This is because nature has already shown how powerful this interplay is: high Tc superconductivity, multiferroelectric, colossal magnetoresistance, and novel behavior in a heterostructure. Of the complex oxides, perovskites are likely the most versatile and engaging materials simply due to the enormous variety of physical phenomena they exhibit.
For many decades people focus on how oxide materials can be investigated by synchrotron X-ray, aiming to understand their sciences for applying a new material. In particular, soft x-ray capabilities have been used to obtain microscopic-level understanding of the strongly correlated systems. In this talk, I will present spectroscopic example which highlights the key role of x-ray magnetic circular dichroism (XMCD) in investigating the magnetism on LaAlO3/SrTiO3 heterostructures. I will also present intercoupling behavior between spin and orbit in the half-doped LaSr2Mn2O7 manganite, which was investigated by the resonant soft x-ray scattering measurement. Finally, I will touch the spin resolved photoemission spectroscopy on FeRh system.
