Topological edge-states of the PT-symmetric Su-Schrieffer-Heeger model: An effective two-state description

Abstract: We consider the non-Hermitian, parity-time (PT) symmetric extensions of the one-dimensional Su-Schrieffer-Heeger (SSH) model in the topological non-trivial configuration. We study the properties of the topologically protected edge states, and develop an effective two-state analytical description of the system that accurately predicts the PT-symmetry breaking point for the edge states. We verify our analytical results by exact numerical calculations.