Samhällsvetenskapliga fakulteten

Seminarium: Berry phase and Wilson loop approach to topological crystalline insulators with time reversal symmetry

  • Datum: –13.00
  • Plats: Ångströmlaboratoriet Å80101
  • Föreläsare: Adrien Bouhon
  • Arrangör: Avdelningen för materialteori, institutionen för fysik och astronomi
  • Kontaktperson: Samara Keshavarz
  • Seminarium

I will present a systematic approach to the identification of the topological insulating phases (with spin-orbit coupling) protected by crystalline symmetries. I show that on top of the Kane-Mele Z2 classification (protected by time reversal symmetry alone), there is an obstructed Z-type topological classification that accounts for all nontrivial windings of the Wilson loop over the Brillouin zone. As a side product, I will show that the "split of an Elementary Band Representation" always must lead to a topological phase (this postulate is at the core of the proposal "Topological Quantum Chemistry" Nature 547, 298 (2017)). I will illustrate these ideas in the case of the honeycomb lattice.