Jie Li (Wu Group) and Pengchong Liu (Jensen Group) - CaST Seminar

Date:

Thursday, March 28, 2019 - 13:00

Location:

2201 Natural Sciences II - Zoom Meeting Broadcast

Speakers:

Jie Li, UC Irvine, Wu Group

Event Title:

1:00PM: Jie Li - The theoretical simulation of single molecular on metal surface | Time: 1:30pm "Interpreting High-Resolution TERS Images by Raman Polarizability Density"

Host:

CaSTL Center | V. Ara Apkarian, Director

Jie Li | Time: 1pm (30 minute presentation)

UC Irvine, Wu group

Title: The theoretical simulation of single molecular on metal surface

Bio: Jie Li is a postdoctoral fellow from Prof Wu group, and obtained his PhD in physics from Fudan University, China. Now, his main research interests are to explore the structural behaviors and electronic properties of single molecular, material surface and two-dimensional materials by using the first-principles.

Abstract: in this talk, I will show three theoretical simulation works on the structural behaviors and electronic properties of single molecular on metal surface that working with the experimental group of Prof Ho. In the first work, I will show the theoretical simulation of isolated pyrrolidine molecule adsorbed on the Cu(001) and Cu(110) surface to understand the reversible transitions between two structural states. In the second work, I will show the structural behaviors and electronic properties of H₂ molecular on the Cu(001) surface to explore the detailed mechanisms and the nature of the dependence of reaction rate on the local environment. In the last work, I will show the structural behaviors and vibration of nickelocene molecules on the Ag(110) surface to understand the corresponding coupling between Spin and Vibration.

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Pengchong Liu | Time: 1:30pm (30 minute presentation)

Penn State, Jensen Group

Title: Interpreting High-Resolution TERS Images by Raman Polarizability Density

Abstract:

Tip-enhanced Raman spectroscopy (TERS) exhibits new selection rule and sub-nanometer spatial resolution, which is attributed to the plasmonic near-field confinement. Despite recent advances in simulations of TERS spectra under highly confined fields, a simply physical mechanism has remained elusive. In this talk I will show that single-molecule TERS images can be explained by local sub-molecular density changes induced by the confined near-field during the Raman process. Specifically, I will demonstrate the approach to generate TERS images by local integration of Raman polarizability density, and discuss how this approach help interpret high-resolution TERS images measured in experiments.

Bio:

Pengchong Liu is currently a PhD candidate in the Department of Chemistry, Penn State University, under the supervision of Professor Lasse Jensen. His research is focused on developing theoretical approaches to the studies of plasmon-enhanced vibrational spectroscopies. Prior to Penn State, he was an experimentalist in materials sciences and engineering. He has a MS degree from the University of Pennsylvania (2015), where he worked on synthesis and assembly of plasmonic nanoparticles. He received undergraduate degrees from Zhejiang University, China (2013).

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Jie Li (Wu Group) and Pengchong Liu (Jensen Group) - CaST Seminar