Colloquium: Physics & Astronomy – Dr. Yang Peng

About the event

The Department of Physics and Astronomy invites you to a colloquium featuring our faculty candidate, Dr. Yang Peng. Dr. Peng will present their talk, “Space-time engineering of topological systems.”

Meet for refreshments before the lecture from 3:45 – 4:10 p.m. in the foyer on floor G above the lecture hall.

In this talk, I will show you the possibility of engineering topological systems with the degrees of freedom of both space and time, which I found to be quite interesting and exciting. Using this approach one is able to create states of matter out of equilibrium, which have no analog under equilibrium condition. In particular, I will show you three examples of space-time engineering. I’ll show you that by driving a system with a specific space-time symmetry,  one can create a higher-order topological phase out of equilibrium[1]. For example, we will see anomalous Floquet corner modes in a 2D driven system.  I will then briefly demonstrate the possibility of creating synthetic dimensions, as well as synthetic electric and magnetic fields by driving a system at multiple frequencies. We will see the 4 dimensional quantum Hall effect appears in a 1D system subject to three drives at different frequencies [2].  I’ll also show that the types of topological protected boundary modes could be multiplexed when the system is driven at multiple frequencies [3].

[1] Yang Peng and Gil Refael, arXiv:1811.11752, 2018 [2] Yang Peng and Gil Refael, Phys. Rev. B 97, 134303, 2018 [3] Yang Peng and Gil Refael, Phys. Rev. B 98, 220509(R), 2018