Frank SCHINDLER
University of Zürich
Crystal defects in topological insulators are known to bind anomalous electronic states with two fewer dimensions than the bulk; the most commonly cited examples are the helical modes bound to screw dislocations in time-reversal invariant weak topological insulators. In my talk, I will explain how one can extend the classification of topological electronic defect states, in particular to time-reversal symmetry breaking magnetic systems. By mapping the Hamiltonians of planes in momentum space to the real-space surfaces between screw or edge dislocations with integer Burgers vectors, I show that crystalline defects can bind higher-order end states with fractional charge. I will present extensive numerical calculations that support these findings.