Figure 2
From: Su-Schrieffer-Heeger chain with one pair of \(\mathcal{P}\mathcal{T}\)-symmetric defects
Spectrum under open boundary condition as a function of θ. (a) γ = 1/4, (b) γ = 1/2, (c) γ = 3/4, (d) γ = 1, (e) γ = 5/4, (f) γ = 3/2, (g) γ = 2, (h) γ = 5/2, (i) γ = 3. Other system parameters are N = 100, Δ = 1/2; the gain and loss are at sites 50 and 51.
