Time:9:30-11:00, Sat, November 15, 2025

Venue:E10-304, Yungu Campus

Host:Dr. Yao Yang, Assistant Professor, Westlake University

Language:English

Speaker：

Yongsoo Yang

Associate Professor

Korea Advanced Institute of Science and Technology

Biography:

Yongsoo is currently affiliated with in the Department of Physics at the Korea Advanced Institute of Science and Technology (KAIST). He earned his Ph.D. in Physics from the University of Michigan, where he specialized in synchrotron X-ray scattering experiments to elucidate surface and interface atomic structures in oxide systems. During his postdoctoral research at UCLA, he expanded his expertise into electron optics and pioneered atomic electron tomography, a technique for achieving single-atom level 3D structural determinations in nanomaterials. At KAIST, Yongsoo's research focuses on advancing multi-dimensional electron imaging, with an emphasis on precise measurement of 3D atomic arrangements at material surfaces and interfaces, as well as atomic-scale determinations of complex topological orderings.

Abstract:

Modern science and technology rely on functional materials, and the physical properties of these materials often strongly depend on defects, local disorder, nanoscale heterogeneities, and grain structures at the atomic scale. Traditional crystallography, which is reliant on periodicity, has been the main method for determining crystal structures, but cannot determine defects or other non-crystalline features. My work goes beyond crystallography. Without any prior assumption of underlying structure, atomic electron tomography (AET) is now able to locate the 3D coordinates of individual atoms and their dynamics with picometer precision and with elemental specificity. A variety of complex atomic structures have been measured with 3D atomic-level details; including surfaces, interfaces, grain boundaries, chemical order/disorder, phase boundaries, topological orders and point defects. I will further demonstrate that AET can also be applied to capture the 4D atomic structural dynamics, unveiling nucleation process at the atomic scale. Understanding the atomic resolution structural dynamics together with the relationship between atomic structure and physical properties will open up new avenues in condensed matter physics and allow the rational design of novel materials at the atomic scale.

Contact:

Yingyi Guo

guoyingyi@westlake.edu.cn