Time:  15:00  (UTC/GMT+8:00, Beijing/Shanghai), Oct. 21 (Thur.) , 2021

Zoom URL: https://us06web.zoom.us/j/9495597503?pwd=UFVMUUVxb3pDUHRkWEFQY3MzRjJYUT09 

Meeting ID: 949 559 7503

Password: 2021

Speaker: Yizhi You (Princeton)

Abstract:

The theory of quantumphasetransitions separating different phases with distinct symmetry patterns at zero temperature is one of the foundations of modern quantum many-body physics. In this talk, I will demonstrate that the existence of a 2Dtopologicalphase transitionbetween a higher-ordertopologicalinsulator (HOTI) and a trivial Mott insulator with the same symmetry eludes this paradigm. A significant new element of ourphasetransitiontheory is that the infrared (IR) effective theory is controlled by short wave-length fluctuations so thecriticalphenomenon isbeyondtherenormalization perspective.

Invited by Prof. Xi-Nan Zhou