Pristupačnost
Date: Wednesday, 29/04/2026
Time: 15:15
Place: F08
Topology in photonic systems and beyond
(Hrvoje Buljan, PMF, Zagreb)
Topology is a branch of mathematics that explores the properties of space preserved under continuous deformations (e.g., stretching and bending). Topological concepts are crucial to explain the behavior of numerous physical systems and phenomena including the quantum Hall effect and topologically protected boundary states, which are robust against localized perturbations. Topology has made a tremendous impact on the development on photonics in the last 15 years, as the analogy between the condensed matter and photonic systems allowed the transfer and further development of topological concepts in photonics. After a broader introduction, I will present some recent results related to so-called sub-symmetry protected topological states [1], hidden multi‑topological phases mediated by constrained inter‑cell coupling [2], and a (topological) formulation of classical electrodynamics that accounts for quantization of charge [3].
[1] Wang, Z., Wang, X., Hu, Z. et al. Sub-symmetry-protected topological states. Nat. Phys. 19, 992–998 (2023).
[2] Wang, Z., Bongiovanni, D., Wang, X. et al. Hidden multi-topological phases mediated by constrained inter-cell coupling. eLight 6, 2 (2026).
[3] B. Golik, D. Jukić, and H. Buljan, Theory of Classical Electrodynamics with Topologically Quantized Singularities as Electric Charges, Laser Photonics Rev. 2024, 2400217.