Mie-tronics supermodes and symmetry breaking in nonlocal metasurfaces

TL;DR

This paper reveals that symmetry breaking in nonlocal metasurfaces can enhance light trapping and enable polarization conversion, challenging traditional beliefs about weaker confinement in such systems.

Contribution

It demonstrates that symmetry breaking in Mie-tronics metasurfaces can strengthen in-plane nonlocal coupling and create new electromagnetic channels for advanced light control.

Findings

Finite arrays show Q-factor enhancement due to redistributed radiation channels.

Symmetry breaking enables polarization conversion in nonlocal metasurfaces.

Diffractive bands and supermodes originate from the same Mie resonances but differ physically.

Abstract

It is usually believed that symmetry breaking in photonic systems leads to weaker optical confinement, such as in the case of metasurfaces when bound states in the continuum are replaced by quasi-bound states with lower quality factors (Q factors). Here we show that symmetry breaking can instead enhance light trapping by strengthening in-plane nonlocal coupling pathways. We consider finite-size arrays of optical resonators supporting Mie resonances (a Mie-tronics platform) and employ diffraction and multiple-scattering analyses. We demonstrate that diffractive bands and Mie-tronics supermodes originate from the same underlying Mie resonances but differ fundamentally in their physical nature. Finite arrays exhibit Q-factor enhancement driven by redistributed radiation channels, and reversing the trends predicted by infinite-lattice theories. We reveal that controlled symmetry breaking opens new electromagnetic coupling channels, enabling polarization conversion in nonlocal metasurfaces. These novel findings establish a unified wave-physics platform linking both scattering and diffraction theories. Also, they outline the design principles for multi-functional metasurfaces that exploit nonlocality for advanced light manipulation, computation, and emission control.