Fig. 4: Edge states and EP.
a, b Complex energy spectra and c, d phase rigidities of the eigenstates for the non-Hermitian SSH model under open boundary conditions. a, c are in the trivial phase, t = 0.8 < tc = 1, while b, d are in the nontrivial phase, t = 1.6 > tc with θ = 0.4. The total number of lattice sites is 2N = 80, and the eigenstates are labeled in increasing order of energy. The red dots are Nth and (N + 1)th states, which are the states nearest to the gap in the trivial phase and the edge states in the nontrivial phase.
