Fractionalized quantum excitations in correlated two-dimensional topological phases

The research field of topological phases and materials is one of the most exciting frontiers in modern condensed matter physics [1]; [2]; [3]; [4]; [5]; [6] ; [7]. In contrast to the classification of conventional condensed matter phases according to their symmetries, different topological states of matter generally do not involve broken symmetries. Rather, they are associated with certain fundamental physical properties that are insensitive to smooth changes in materials parameters. Therefore, a topological state cannot change into another unless the system undergoes a quantum phase transition [6] ; [7].