Tunable exceptional lines in non-Hermitian diamond photonic lattices
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-07-28 |
| Journal | Optics Letters |
| Authors | Yingying Zhang, Shiqiang Xia, Pengbo Jia, Zeyun Shi, Lu Qin |
| Institutions | Hubei University of Automotive Technology, Henan Normal University |
Abstract
Section titled âAbstractâHigher-order exceptional point (EP) geometries, comprising lines, rings, or surfaces formed by EPs, have garnered significant attention due to their rich topological properties and potential sensing applications. However, constructing such geometries remains challenging, as it requires additional degrees of freedom in the Hamiltonianâs parameter space or higher symmetry levels, particularly in discrete systems. Here, by introducing controlled asymmetric couplings, we investigate the symmetry and exceptional lines (ELs) in non-Hermitian diamond photonic lattices. The second- and third-order ELs emerge when parity-time and pseudo-chirality symmetries are satisfied. These lines can be dynamically tuned by adjusting non-reciprocal coupling strength and inter-cell coupling ratios. Our work provides a platform for exploring higher-order EP-related phenomena, such as enhanced sensitivity in topological sensors and chiral mode switching in discrete non-Hermitian systems.