Recently, the International Joint Research Center for Nanophotonics and Metamaterials (Meta-Nano Center) at Harbin Engineering University (HEU), in collaboration with international teams from ITMO University (Russia), The Australian National University, and other institutions, has made significant advances in the fields of non-Hermitian photonics and Mie resonance regulation. The research team successfully designed the structure of subwavelength dielectric resonators and, for the first time, experimentally demonstrated the dynamic conversion between non-Hermitian exceptional points (EPs) and diabolic points (DPs) in the scattering spectrum, both exhibiting superscattering characteristics. This breakthrough offers a new theoretical framework for the development of highly sensitive sensors, electromagnetic stealth technologies, multi-physical-field energy regulation systems, and nonlinear optical devices. The results were published on February 21 in the prestigious journal Science Advances under the title "Non-Hermitian Singularities in Scattering Spectra of Mie Resonators," with HEU as the lead institution.
Traditional research suggests that singularities in non-Hermitian systems require complex coupling structures. In contrast, this study demonstrates that by adjusting the geometric parameters of a single ring-shaped dielectric resonator, the scattering spectra of EPs and DPs can be directly observed in the microwave frequency band (Figure 1). Experimental data reveal that EPs correspond to the anapole state (a scattering dark state), while DPs exhibit superscattering, which results from the superposition of multiple resonance modes. This discovery integrates non-Hermitian physics with Mie photonics, opening new possibilities for controlling light-matter interactions.
"By dynamically switching between EPs and DPs in ring resonators, we can potentially design reconfigurable electromagnetic stealth surfaces or develop subwavelength-scale energy transmission devices," said Professor Song Mingzhao, the corresponding author of the paper. This achievement was verified through a full-link closed-loop approach encompassing theory, simulation, and experimental measurement on the Ultra-Nano Center's shared scientific research platform at HEU. These technologies are expected to find applications in wireless power systems for medical implants, among other fields.
The Ultra-Nano Center at HEU has established an international joint innovation team focused on the theory and application of multi-physics field metamaterials. The team conducts both fundamental and applied research in areas such as energy enrichment and transmission across multiple physical fields, as well as nano-optoelectronic energy devices, achieving a series of groundbreaking results. Over 50 papers have been published in top-tier journals, including Nature Electronics, Nature Photonics, Nature Materials, Nature Nanotechnology, Science Advances, Nature Communications, and Physical Review Letters, with HEU as the primary or corresponding institution.
Science Advances is a leading international journal that publishes research across a wide range of natural science disciplines, with an impact factor of 11.7.
Paper Link:
https://www.science.org/doi/10.1126/sciadv.adr9183
