Simultaneous Manipulation of Line‐Gap and Point‐Gap Topologies in Non‐Hermitian Lattices

Abstract

AbstractNon‐Hermiticity may significantly influence the topology of a photonic/electronic lattice, giving rise to point gaps, which have attracted much attention in recent years. While the influences of the point‐gap topology on the bulk‐boundary correspondence for the line gap have been widely studied, the topological lattice that simultaneously processes the line‐gap and point‐gap topological transitions has not been reported. Here, a strategy to simultaneously manipulate the line‐gap and point‐gap topologies in non‐Hermitian lattices is proposed. By introducing the asymmetric intercell coupling, the line‐gap topological transition process is demonstrated. By further considering the nonreciprocal coupling between the nearest neighboring unit cells, the point‐gap and line‐gap topological transitions can be simultaneously realized. Finally, the influence of the next nearest coupling on non‐Hermitian line‐gap and point‐gap topologies is also discussed.