分子科学研究所

サイト内検索

研究・研究者

研究会・セミナー

セミナー・イベント詳細

第909回分子研コロキウム

演 題 「Small and Fast: Coherent Å-fs Chemistry」
(今回のコロキウムは森野レクチャーとしても開催されます.) 
日 時 2017年10月12日(木) 16:00
講演者 Prof. Wilson Ho (University of California, Irvine)
場 所

分子科学研究所 研究棟2階201号室

概 要

Inhomogeneity of different length scales is one of the fundamental characters of space and matter that has its origin in the spatial variations of the charge and mass distributions. While many changes in nature and in the laboratory can be observed with the naked eyes, ultimately the interactions that lead to these changes occur at the atomic scale. In addition, heterogeneity influences the time scale that transformations occur at different locations, and the average time may differ significantly from the local times. The desire to understand and control changes in the charge and mass distributions would require experimental tools that possess simultaneous spatial and temporal resolutions to reveal the heterogeneity.

The relevant scales in chemistry relate to the motions of atoms in molecules that occur at fraction of a vibrational period and <0.1 nm distance. This joint Å-fs resolution can be achieved by the combination of a femtosecond laser with a low temperature scanning tunneling microscope (fs-STM) in ultrahigh vacuum that probes chemical transformations of single molecules. As a first demonstration, the dynamics of the conformational change in a single molecule adsorbed on a metal surface was followed in the time domain, revealing the vibrational reaction coordinate and the temporal decay of the coherently excited state that drives the conformational change [1]. In addition, the effects on the single molecule dynamics by a nearby molecule were determined. These experiments demonstrate the fs-STM approach in probing the effects of heterogeneity in space and time on the chemical dynamics in single molecules.

Reference
[1] S. Li, S. Chen, J. Li, R. Wu, and W. Ho, Phys. Rev. Lett., submitted (2017).

詳しい内容はこちらをご覧下さい。

お問合せ先

柳井毅、藤貴夫(2017年度コロキウム委員)