banner8 banner8_m

News and Events

UPCOMING EVENTS

BACK
Seminars

Public Seminar of RPg Student: Classifying topological insulators through Atiyah-Hirzebruch spectral sequence

Speaker Mr. Junkun LYU
Affiliation The University of Hong Kong
Date January 10, 2025 (Friday)
Time 10:30 a.m.
Venue Room 105, 1/F, Chong Yuet Ming Physics Building, The University of Hong Kong

Abstract
In previous works concerning Atiyah-Hirzebruch spectral sequence (AHSS) as a useful tool in the context of band theory, people get the complete list of topological invariants for 230 space groups and even the K groups for nearly 59% of symmetry settings in three spatial dimensions.


The generalization of the Brillouin Klein bottle to three dimensions has led to various attempts. Here, we propose a complete framework, ten Brillouin platycosms,which are the elementary shapes of the 3D momentum space units, to classify the topological insulators over them.Applying the Atiyah-Hirzebruch spectral sequence (AHSS), we show that the reduced K group of each platycosm is isomorphic to the second cohomology group of the corresponding Bieberbach group. Thus, by calculating the updating pages of the AHSS, we get the following reduced K groups.

 

Anyone interested is welcome to attend.