Topological classification of crystalline insulators through band structure combinatorics

Back to Events

Jorrit Kruthoff
University of Amsterdam
Tuesday, July 18, 2017 - 2:00pm
402 Old LeConte Hall

In this talk I will discuss the classification of topological phases protected by a space group symmetry in the absence of time-reversal and particle-hole symmetry. The space group symmetries cause the bands to arrange themselves in a systematic way along the Brillouin zone. I will exploit this systematic arrangement to come up with a method that classifies all topological phases protected by space group symmetry only. To illustrate the method I will discuss a particular example in two dimensions. A further application of our method allows us to study the transitions between these topological phases. I will argue that in two dimensions there can be direct transitions, but also intermediate semi-metallic phases that host Weyl nodes. I will also talk on work in progress in which we include time-reversal symmetry in the classification.