Fig. 5: Sketch of generic 1D lattice models and the criterion of STL.
From: Scale-tailored localization and its observation in non-Hermitian electrical circuits

a A generic 1D non-Hermitian lattice model. The largest hopping ranges to the left and right are ML and MR. The additional asymmetric coupling is marked in red. b Sketch of the criterion of STL. The (MR + 1)-th roots of the Bloch spectra reside on the unit circle (red circle).