研究・研究者
研究会・セミナー
| 演 題 | 「Structural dynamics of photoinduced molecular switching in the solid state」 |
|---|---|
| 日 時 | 2009年08月21日(金) 14:00 |
| 講演者 | エルベ・カイヨー教授（フランス、レンヌ第一大学、物理学科） |
| 場 所 | 研究棟201セミナー室 |
| 概 要 | A current challenge in science and technology is to direct the functionality of matter at the relevant smaller scale, not only ultra-small size but also ultra-short time. Thus a femtosecond laser pulse may induce spectacular collective and/or cooperative phenomena in the solid state. This can trigger the transformation of the material towards another macroscopic state of different electronic and/or structural order, for instance from non magnetic to magnetic or from insulator to conductor. Besides different itinerant electron systems materials with multi-functional molecules which can switch between two states are also promising. The switching of molecules in a material triggered by a femtosecond light pulse ensues the now established field of femtochemistry in solution where photo-chemical processes are essentially independent. The physical picture of the dynamics of this switching in molecular materials will be discussed. The key point is that in the solid state different degrees of freedom of different nature play their part on different time scales and the pathway is complex, from the molecular to material length and time scales. The discussion will be based on recent investigation of the structural dynamics in multifunctional spin crossover compounds which are prototypes of molecular bistability in the solid state. The time-resolved x-ray diffraction and optical results show the dynamics span from subpicosecond molecular photoswitching followed by volume expansion (nanosecond) and thermal switching (microsecond). |
| お問合せ先 |
米満賢治（理論・計算分子科学研究領域） |
