Fig. 6: Response to disorder and the Berry curvature for the generalized Kitaev models.

Energy eigenvalues for the a double Kitaev (DK), b constant s-wave (CSW), and c CI domain-wall configurations with respect to the disorder strength λ. The energy eigenvalues for λ = 0 are equal to the energy eigenvalues given in Fig. 5d. In a, c, the topological zero-energy domain-wall states are stable for reasonable strength of disorders, while the two edge states spread out as λ increases because the disorder hybridizes two edge states. In b, all ingap states are not robust out as λ increases because they are non-topological. Normalized Berry curvature distributions for the d DK, e CSW, and f CI systems under the adiabatic evolution time parameter (t). Berry curvature distributions for the subblocks are given on the right. In d, f, the sharp points indicate the singular point where the gap is closed and a topological phase transition occurs. The Berry curvature is blurred in (e), implying no topological phase transition and non-quantization of the Berry phase difference. The parameters and the domain-wall configurations are the same as in Fig. 5.