Delocalization of topological edge states

The non-Hermitian skin effect (NHSE) in lattice systems depicts the exponential localization of eigenstates at system's boundaries. It has led to a number counter-intuitive phenomena and challenged our understanding bulk-boundary correspondence topological systems. This work aims investigate how NHSE in-gap edge states compete with each other, several representative static periodically driven 1D models, whose properties are protected by different symmetries. emerging insight is that critical system parameters, even topologically can be perfectly delocalized. In particular, it discovered this intriguing delocalization occurs if real spectrum falls on same complex spectral loop obtained under periodic boundary condition. We have also performed sample numerical simulation show such delocalized safely reconstructed from time-evolving states. Possible applications briefly discussed.