(a) Chern number versus m and γ with sample size N = 30. The red solid line corresponds to the analytical prediction. (b) The selected plot of (a) by setting γ = 0.6 for different sample size N. (c) and (d) The absolute value of V⁻¹HV − J in the diagonal direction and the sum of the remaining matrix elements, respectively. The value larger (smaller) than the maximum (minimum) value of the color bar is marked by grey (black) color. The other parameters are the same as those in Fig. 2.