Tue, 22 Feb 2022
12:00
12:00
Virtual
Anomalous boundaries of topological matter
Guo Chuan Thiang
(University of Peking)
Abstract
A topological insulator has anomalous boundary spectrum which completely fills up gaps in the bulk spectrum. This ``topologically protected’’ spectral property is a physical manifestation of coarse geometry and index theory ideas. Special examples involve spectral flow and gerbes, related to Hamiltonian anomalies, and they arise experimentally in quantum Hall systems, time-reversal invariant mod-2 insulators, and shallow-water waves.