Fig. 6: Distribution of poles under anomalous non-Hermitian skin effect.
From: Anomalous non-Hermitian skin effect: topological inequivalence of skin modes versus point gap
a z1, z2, z3 and z4 being encircled by the unit circle, which induces the nonzero spectral winding, or the nontrivial point gap. Parameters are \({E}_{b1}=\frac{1}{6}i\), γ1 = γ4 = 0, ta = 1, \({t}_{b}=\frac{1}{2}\), tc = 2, γ2 = 2, γ3 = 1, Va = 2 and Vb = Vc = 1. b z1, z3 and z5 being encircled by the unit circle, while z2 and z4 being excluded for reference point \({E}_{b2}=\frac{1}{6}i\). Thus, the system corresponds to the trivial point gap. Parameters are γ1 = γ3 = 0, ta = tc = 8, \({t}_{b}=\frac{1}{2}\), γ2 = 2, γ4 = 1, \({V}_{a}={V}_{c}=\frac{3}{5}\) and Vb = 1.
