Hybridization of non-Hermitian topological interface modes

Topology has transformed photonics by introducing robust edge states and enhanced protection. Inspired by the Jackiw-Rebbi mode—a topological interface state found in one-dimensional systems—we investigate its realization in a non-Hermitian photonic setting to enable greater control and improved optical functionalities. We present and experimentally verify the hybridization of non-Hermitian Jackiw-Rebbi states and their farfield radiation properties. This hybridization not only modifies energy levels under a strong coupling scheme but also significantly reshapes farfield radiation characteristics. The bonding mode exhibits sub-radiant, omnidirectional emission, while the antibonding mode becomes super-radiant and highly unidirectional. Crucially, this non-Hermitian hybridization is tunable, allowing simultaneous control of energy splitting, quality factor, and farfield radiation by varying the distance between the two topological interfaces. Our findings establish hybridized radiating topological interface states as a robust platform for engineering two-level systems with tailored farfield responses, offering new possibilities for applications in beam shaping, nonlinear optics, quantum technologies, and beyond.