Resonant Electric-Magnetic Toroidal Duality in Height-Modulated Hexagonal Metasurfaces
Abstract
Toroidal modes enable high-Q resonances, but electric toroidal excitations remain unexplored compared to magnetic ones. This work establishes electric-magnetic toroidal duality in a hexagonal metasurface. Using finite element simulations, we analyze electric and magnetic toroidal modes in a hexagonal silicon nanorod supercell under mirror-symmetry breaking via height modulation. Eigenfrequencies, Q-factors, power flow, and polarization responses are computed. We identify electric TO and ATO modes with complementary near-field topologies to magnetic analogues. Direct frequency intersections (magnetic and electric TO/ATO) yield high-Q quasi-BICs. Polarization selectivity reverses between families: 0{\deg} excites magnetic TO/electric ATO; 90{\deg} excites magnetic ATO/electric TO. A loss hierarchy (magnetic TO > magnetic ATO > electric ATO > electric TO) and protective layers compatibility are demonstrated. Electric and magnetic toroidal responses are dual manifestations of the same symmetry, providing a unified design framework for high Q metasurfaces in sensing, nonlinear optics, and loss-tolerant devices.
Keywords
Cite
@article{arxiv.2605.19699,
title = {Resonant Electric-Magnetic Toroidal Duality in Height-Modulated Hexagonal Metasurfaces},
author = {Oleksiy Breslavets and Yuri Savin and Zoya Eremenko},
journal= {arXiv preprint arXiv:2605.19699},
year = {2026}
}
Comments
16 pages, 9 figures, 2 tables