Calendar of Events
Collective Modes on the Surface of a Topological Insulator
Speaker: Hsiang-Hsi (Sean) Kung (University of British Columbia)
Topological insulators are novel quantum materials with robust metallic surfaces while the bulk remain insulating. Due to the strong Rashba spin orbit coupling, the surface electrons in these materials are characterized by chiral spin textures leading to various technological applications. Such novel electronic systems allow realization of new collective modes such as chiral spin modes [PRL 119, 136802 (2017)] and chiral excitons [PNAS 116, 4006 (2019)] that are absent in conventional metals, providing the playground for studying the interplay between charge and spin degrees of freedom. In this talk, I will review the recent spectroscopic experiments aimed to identify the collective modes in a prototypical topological insulator, Bi2Se3, with the emphasis on the development of using optical techniques to resonantly excite the otherwise “hidden” modes. The comparison to other topological insulator materials and the generalization to 3D Rashba systems will also be discussed.
- Host: Girsh Blumberg
- Tea, coffee, and cookies served at 10:20
- All welcome!