Figure 13
From: Second order topology in a band engineered Chern insulator
Band gap calculated for the fermionic dispersion in the TI phase and the SOTI phase are shown. (a) Here \(\xi =1.5\) and \(t_2=0\). This shows that there are Dirac nodes at the K and K\('\) points in the BZ. (b) Here \(\xi =1.5\) and \(t_2=0.1\). Clearly the gap has now opened. In (c,d) the system is in the SOTI phase. Here \(\xi =2.5\) and \(t_2=0\) and 0.1, respectively. Clearly, no topological phase transition occurs. Thus the two Hamiltonians corresponding to these parameters can be adiabatically connected. Here t, \(\phi \) and m are fixed at 1, \(\frac{\pi }{2}\) and 0, respectively.
