Abstract
Non-Hermitian singularities – exceptional points (EPs), bulk Fermi arcs, Rayleigh anomalies, and bound states in the continuum (BICs) – exhibit unique wave phenomena with transformative potential in photonics [1,2]. While EPs enable extreme sensitivity, Fermi arcs bridge Hermitian and non-Hermitian topology, and BICs offer infinite radiative quality factors. Here, we theoretically and experimentally investigate these singularities within isolated dielectric and periodic metastructures. Specifically, we predict exceptional BIC (EP-BIC) states in vertically coupled dielectric metasurfaces [3], experimentally demonstrate bulk Fermi arcs in single dielectric resonators [4], and explore the previously unstudied link between EPs and anapole states [5].
References
[1] E. J. Bergholtz et al., Rev. Mod. Phys. 93, 015005 (2021).
[2] H. Zhou et al., Science 359, 1009 (2018).
[3] A. Canós Valero et al., Phys. Rev. Lett. (in press, 2025).
[4] N. Solodovchenko et al., arXiv:2502.12711 (2025).
[5] F. Zhang et al., Sci. Adv. 11, eadr9183 (2025).
Andrey Bogdanov is a professor at ITMO University and Harbin Engineering University. He obtained Bachelor's and Master's degrees with honors in Solid State Physics at Saint-Petersburg State Polytechnical University. He received his PhD from Ioffe Institute in 2012. The thesis was devoted to the theoretical analysis of quantum cascade lasers. This work was awarded the “Young Scientist Award” by the European Optical Society. Andrey Bogdanov is the head of the Theoretical Nanophotonics group and specializes in studying optical nanoantennas, surface waves, nonlinear optics, metasurfaces, bound states in the continuum, and related directions. Andrey Bogdanov has authored over 200 journal papers (Science, Sci. Adv., Adv. Mat., Phys. Rev. Lett., Nano Letters, and others), over 100 conference presentations, and two patents. He is a PI in more than 20 projects supported by National foundations in China and Russia. In 2021, he received the Leonard Euler Prize for young scientists "For research of dielectric nanoantennas and nanoresonators for localization and control of electromagnetic radiation on subwavelength scales." He is a fellow of the BASIS Foundation for Theoretical Physics and Mathematics and a laureate of the Government awards for scientific and pedagogical activities. He is the author of two online courses, the head of the international master program “Nanophotonics and Metamaterials,” the chair of the annual International Summer School on Nanophotonics and Metamaterials, and the Editor of Photonics and Nanostructures – Fundamentals and Applications journal.