Understanding Raman Scattering in Low-Dimensional Materials

Vincent Meunier, Ph.D.

Professor and Chair of Engineering Science & Mechanics at The Pennsylvania State University

Due to spatial confinement, low-dimensional materials have attracted significant attention as emerging quantum materials. Thanks to spectacular progress in the development of atomically precise bottom-up synthesis methods, accurate knowledge of atomic content and configurations is now readily available, making it possible to create a strong link between theoretically predicted properties and their experimental observation. Several characterization techniques have been employed to improve the understanding of these materials, to establish their crystal structure, purity, and internal configurations. In particular, Raman spectroscopy has demonstrated that structural vibrations are reliable indicators of their structure and, in turn, of their fundamental properties. In this talk, I will provide an overview of the theoretical and computational research performed in my group in the area of phonon calculations and demonstrate how quantum mechanical studies and Raman scattering are combined to determine the fundamental structural properties in an array of low-dimensional materials. In addition to discussing examples of such studies performed on twisted bilayer systems, transition metal dichalcogenides, graphene nanoribbons, and quantum dot over the past few years, I will also briefly discuss our ongoing efforts in the use of high-throughput and machine-learning methods and discuss the importance of ultra-low-frequency vibrational modes in the study of these materials.

Bio:  Meunier is a Professor of Engineering Science and Mechanics; Physics; and Materials Science and Engineering at The Pennsylvania State University where he holds the P.B. Breneman Chair. Meunier earned his Ph.D. in Physics from the University of Namur in Belgium in 1999 and was a senior research and development staff member at Oak Ridge National Laboratory until 2010 when he joined Rensselaer Polytechnic Institute before moving to Penn State in 2022. He has published more than 350 papers in peer-reviewed journals, with about 32,000 citations. He is a Fellow of the American Physical Society (APS), the Institute of Physics (IoP), and the American Association for the Advancement of Science (AAAS). Meunier leads the Innovative Computational Material Physics (ICMP) group at Penn State where his research uses quantum theory and computation to examine the atomic-level details of materials with a particular emphasis on low-dimensional carbon nanostructures, which have been among his main research for almost 30 years. He is the founding and current Editor-in-Chief of the journal Carbon Trends since 2020.