Rabi splitting and unidirectional reflectionless propagation in one-dimensional topological plasmonic crystal

Abstract

In this paper, we study the strong coupling between the topological edge state and Fabry–Perot cavity state in a one-dimensional plasmonic crystal heterostructure. Finite element method simulations show that a significant plasmonic Rabi splitting is achieved in the near-infrared region and Rabi energy can reach up to 45.5 meV. A dual-band near-perfect absorption phenomenon can be observed, and a coupled oscillator model is proposed to explain the origin of Rabi splitting. In addition, the dual-band unidirectional reflectionless plasmonic propagation in the Rabi splitting region is investigated, and the non-Hermitian scattering matrix is used to verify the existence of double exceptional points. The study may find applications in plasmonic switchers, on-chip sensors, diode-like devices, and filters.