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Siyu Chen | Time: 1pm
UC Irvine - Ho Group
Title: Single molecule chemistry at space-time limit with fs-STM
Bio: Siyu Chen received her bachelor’s degree in physics at Nankai University, China, 2015. She joined Prof. Wilson Ho’s group in 2015, where she has been studying the single molecule dynamics with joint fs-angstrom resolution, using a fs-laser combined scanning tunneling microscope (fs-STM).
Abstract: The investigation of single molecule dynamics with joint spatial-temporal resolution pushes the limit of measurement in nanoscale phenomena. By shining femtosecond laser pulse pairs with adjustable time delay into the junction of a scanning tunneling microscope (STM) with an adsorbed molecule on the surface, the dynamics of its chemical transformation can be followed in space-time. As an example, we probe the reversible conformational change in an isolated pyrrolidine molecule adsorbed on a Cu (100) surface. A periodic, decaying oscillation was observed in the transition rate as a function of the time delay, thereby revealing that the conformational change was coherently driven by the excitation of a particular vibrational mode in the molecule. The atomic scale resolution was demonstrated by observing the influence on the dynamics of a molecule by a nearby molecule.
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