Non-Hermiticity-induced topological transitions in long-range Su-Schrieffer-Heeger models

Abstract

The interplay of topology and non-Hermiticity opens a new avenue for engineering novel topological matter and generating various unique effects. Here, we demonstrate that the non-Hermiticity can induce rich topological phase transitions in a long-range Su-Schrieffer-Heeger model. We find that the non-Hermiticity is able to drive topological transitions between different winding numbers: $\ensuremath{\nu}=0\ensuremath{\rightarrow}1$ and $2\ensuremath{\rightarrow}1$. These topological phase transitions can be characterized by the bulk band gap, edge states, complex Zak phase, and hidden Chern number. Interestingly, by extending to more general long-range Su-Schrieffer-Heeger lattices, the non-Hermiticity can drive exotic transitions associated with the corresponding Hermitian topological phases. Finally, we demonstrate the experimental feasibility of our scheme in an electric circuit system. Our paper could be useful for the study of non-Hermitian topological states and their device applications.