Speaker: Junyeong Ahn(Harvard University)

Host: Rebecca Flint

Title: Shedding Light on Topology: Exploring Topological Materials with Light-Matter Interactions

Abstract: Exploration of topological materials is a central theme of modern quantum condensed matter physics, and it is currently encountering new horizons. Traditionally, the field has focused on static and DC-transport properties, based on the understanding that topological phases are defined by ground-state properties. However, this talk will spotlight an emerging topic: the dynamic properties of topological materials. Through studying light-matter interactions, I will demonstrate how we can use dynamic properties to shed light on the topological properties of materials and bridge these to broader quantum phenomena. In particular, I will highlight intriguing optical phenomena in topological magnets and superconductors.

Bio: Junyeong Ahn is a postdoctoral fellow in the Department of Physics at Harvard University. After receiving his Ph.D. at Seoul National University, he was a postdoctoral fellow at The University of Tokyo and RIKEN. His Ph.D. studies identified a new topological invariant of real Bloch wavefunctions, the Euler number, which is a key ingredient of the flat bands in magic-angle graphene. His recent work has focused on novel optical properties of quantum materials arising from the geometry and topology of quantum states with potential applications to technology.