Hybridization of Non-Hermitian Topological Interface Modes

TL;DR

This paper demonstrates tunable hybridization of topological interface states in gain media, enabling control over energy levels and radiation patterns, with potential applications in optics and quantum technologies.

Contribution

It introduces the experimental realization of hybridized radiating topological interface states with tunable properties in non-Hermitian systems.

Findings

Hybridization modifies energy levels under strong coupling.

Bonding mode shows sub-radiant, omnidirectional emission.

Antibonding mode becomes super-radiant and unidirectional.

Abstract

We propose and experimentally demonstrate the hybridization of radiating topological interface states, analogous to Jackiw-Rebbi states but in gain media with radiation fields. This hybridization not only modifies energy levels under a strong coupling scheme but also significantly reshapes far-field 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 far-field 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 far-field responses, offering new possibilities for applications in beam shaping, nonlinear optics, quantum technologies, and beyond.