-
Semiconductors and Microelectronics Technology Seminar - Omer Yaffe, Wednesday, March 12th at 10am in EEB 132
Wed, Mar 12, 2025 @ 10:00 AM - 11:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Omer Yaffe, Department of Chemical and Biological Physics Weizmann Institute of Science
Talk Title: Anharmonic Vibrational Dynamics in Crystals: What It Is, Why It Matters, and How Raman Spectroscopy Uncovers It
Series: Semiconductors & Microelectronics Technology
Abstract: Anharmonic vibrational dynamics play a crucial role in determining the physical properties of crystalline materials, impacting thermal conductivity, phase transitions, ion transport, and optoelectronic behavior.In this talk, I will present an intuitive framework for understanding anharmonicity and demonstrate how Raman spectroscopy, combined with coupled mode models, provides a powerful tool for probing these dynamics. I will illustrate this approach through three case studies: (1) the temperature evolution of hydrogen-bond vibrations in glycine crystals, (2) soft modes and phase transitions in bismuth vanadate, and (3) electron-phonon coupling in heavily doped silicon.A key takeaway from this analysis is that modeling with coupled mode pairs, rather than a single damped oscillator, effectively captures material behavior, bridging equilibrium and non-equilibrium dynamics and providing deeper insight into complex vibrational interactions in crystals.
Biography: Omer Yaffe is an Associate Professor at the Weizmann Institute of Science, where he leads a research group focused on anharmonic lattice dynamics. His work combines experimental techniques, particularly advanced Raman spectroscopy, with theoretical modeling to explore how lattice vibrations influence charge transport, phase transitions, and ion conduction.
Host: Jayakanth Ravichandran, Joshua Yang, Chongwu Zhou, Steve Cronin and Wei Wu
More Information: Omer Yaffe_2025-03-12.pdf
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 132
Audiences: Everyone Is Invited
Contact: Marilyn Poplawski
This event is open to all eligible individuals. USC Viterbi operates all of its activities consistent with the University's Notice of Non-Discrimination. Eligibility is not determined based on race, sex, ethnicity, sexual orientation, or any other prohibited factor.
