Condensed Matter seminars

Topological classification of nodal band structures based on symmetry

by Adrien Bouhon (Uppsala University)

112:028 (Nordita South) ()

112:028 (Nordita South)

We show that representation theory for space groups and Wilson loop techniques can be combined leading to a topological classification of band structures. The global band topology is effectively determined by the sets of occupied Irreducible Representations (IRREPs) at a few high-symmetry points. Also explicit topological invariant can be derived algebraically from the IRREPs. This approach leads to the prediction of many symmetry-protected band crossings going beyond the essential degeneracies listed in the tables of space group IRREPs.