Topological phase in a non-Hermitian PTPT symmetric system

• We discuss a novel topological aspect for the non-Hermitian Aubry–Andre model.
• We show that there exists topologically nontrivial edge states with real eigenvalues.
• We show that topological phase transition occurs by varying the impurity position.

In this work, we consider a tight binding lattice with two non-Hermitian impurities. The system is described by a non-Hermitian generalization of the Aubry–Andre model. We show that there exists topologically nontrivial edge states for the system in the PTPT symmetric region.