Frequency domain winding number and interaction effect on topological insulators

We study the effect of interactions on the time-reversal invariant topological insulators in four and three spatial dimensions. Their topological indices are expressed by the interacting Green's functions. Under the local self-energy approximation, we find that interaction could induce nontrivial frequency-domain winding numbers and change the topological classes of the system. Our results suggest that the topological phases could be destroyed without developing long-range orders. Practical issues on the accurate frequency-momentum integration combined with dynamical-mean-field theory and diagrammatic calculations of the interacting Green's functions are also addressed.