Correlation-driven phase transition in a Chern insulator

The phase transition driven by electron correlations in a Chern insulator is investigated within the dynamical mean-field theory. The Chern insulator is described by the Haldane model and the electron correlations are incorporated by introducing the short-range interaction between the itinerant electrons and localized fermions. In the preservation of the inversion symmetry, the electron correlations drive the system from the Chern insulator to a renormalized pseudogap metal, and then to the topologically trivial Mott insulator. When the inversion symmetry is broken, a charge ordering and a nontrivial Chern topological invariant coexist.

Figure 1

The DOS for various values of $U$ ($t=1$, $t_2=0.5$).

Figure 2

The imaginary part of the self-energy $\mathrm{Im}\Sigma \left(i\omega \right)$ for various values of $U$ ($t=1$, $t_2=0.1$).

Figure 3

The absolute value of the renormalized factor $\left|Z\right|$ as a function of $U$ ($t=1$, $t_2=0.1$).

Figure 4

The phase diagram of inversion symmetry states at half filling. CI denotes the Chern-insulating phase, and MI denotes the Mott-insulating phase. The pseudogap metallic phase exists between the two phases ($t=1$).