PHYSICS/BK21 SEMINAR (08/09/10)
관련링크
본문
"The present and the future of optical spectroscopy on condensed matter physics
연사: Dr. Jong Seok Lee[Tokyo University]
일시: 2008 년 9 월 10 일 14:00-15:00
장소: 물리학과 세미나실(3-201호)
ABSTRACT:
Optical spectroscopy has been used as one of the most powerful experimental tools in material science since a long time ago. In this talk, I will show recent development of optical spectroscopy in the respect of both the analytical approach and related technology. In the first part, I will discuss the optical probe of the orbital correlation and its ordering. While the orbital emerges as an important degree of freedom to understand novel phenomena in strongly correlated electron system, its real-space correlation is not easy to detect because of the extended nature of its spatial distribution. I will demonstrate that optical spectroscopy can be a good tool to address this issue by adopting a new analysis scheme based on the orbitally degenerate Hubbard model and also by exploiting highly-sensitive polarization-modulated mid-infrared microspectroscopy. In the second part, I will demonstrate the usefulness of the combination between microspectroscopy and a lab-on-a-chip based on the oxide thin film. By applying an electric pulse to the VO2 thin film between two electrodes separated by a micrometer scale, I could induce the multi-level resistance switching which is found to originate from the formation of the local conducting paths. With an application of electric pulse high enough to induce the complete phase transition to the metallic state, the local heat pulse was generated and I could visualize its propagation as a function of time. I will briefly introduce its application to investigate the domain dynamics of the thermotropic liquid crystal. Finally, I will demonstrate a recent development related with the accelerator-based light sources, mainly the infrared free electron laser and the coherent terahertz radiation which both are enormously brilliant compared to conventional light sources. I will show a basic characterization of these light sources and introduce two proof-of- principle experiments of the spectroscopic set-up fitting to the source characteristics and the scientific demands.
문의처: 이기봉(054-279-2068, kibong@postech.ac.kr)
"
연사: Dr. Jong Seok Lee[Tokyo University]
일시: 2008 년 9 월 10 일 14:00-15:00
장소: 물리학과 세미나실(3-201호)
ABSTRACT:
Optical spectroscopy has been used as one of the most powerful experimental tools in material science since a long time ago. In this talk, I will show recent development of optical spectroscopy in the respect of both the analytical approach and related technology. In the first part, I will discuss the optical probe of the orbital correlation and its ordering. While the orbital emerges as an important degree of freedom to understand novel phenomena in strongly correlated electron system, its real-space correlation is not easy to detect because of the extended nature of its spatial distribution. I will demonstrate that optical spectroscopy can be a good tool to address this issue by adopting a new analysis scheme based on the orbitally degenerate Hubbard model and also by exploiting highly-sensitive polarization-modulated mid-infrared microspectroscopy. In the second part, I will demonstrate the usefulness of the combination between microspectroscopy and a lab-on-a-chip based on the oxide thin film. By applying an electric pulse to the VO2 thin film between two electrodes separated by a micrometer scale, I could induce the multi-level resistance switching which is found to originate from the formation of the local conducting paths. With an application of electric pulse high enough to induce the complete phase transition to the metallic state, the local heat pulse was generated and I could visualize its propagation as a function of time. I will briefly introduce its application to investigate the domain dynamics of the thermotropic liquid crystal. Finally, I will demonstrate a recent development related with the accelerator-based light sources, mainly the infrared free electron laser and the coherent terahertz radiation which both are enormously brilliant compared to conventional light sources. I will show a basic characterization of these light sources and introduce two proof-of- principle experiments of the spectroscopic set-up fitting to the source characteristics and the scientific demands.
문의처: 이기봉(054-279-2068, kibong@postech.ac.kr)
"
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