Observation of Moir\'e Plasmonic Skyrmion Clusters

TL;DR

This paper introduces moiré plasmonic skyrmion clusters, demonstrating their formation, topological control, and rapid skyrmion number inversion in nanostructures through theoretical and experimental methods.

Contribution

It presents the first concept and experimental realization of moiré plasmonic skyrmion clusters with tunable topological properties and lattice configurations.

Findings

Demonstration of crystallized and quasi-crystallized skyrmion lattices

Rapid skyrmion number inversion in misaligned nanostructures

Topological control via twistronics engineering

Abstract

Skyrmions are topological defects belonging to nontrivial homotopy classes in particle theory. Their remarkably stable topology has recently been observed in electromagnetic waves. For the evanescent fields near a surface, this has been realized so far only for elementary optical skyrmions, with a fixed skyrmion number. Here we report, both in theory and experiment, the concept of moir\'e plasmonic skyrmion clusters, where multi-skyrmions are nested to form a large optical skyrmion cluster. By leveraging twistronics engineering of plasmonic nanostructures, we demonstrate both crystallized and quasi-crystallized optical skyrmion lattices, revealing an unprecedented degree of topological control. In a misaligned composite nanostructure, the rapid inverting of optical skyrmion number is achieved, which is explained by a lattice model. This topological change of moir\'eplasmonic skyrmion clusters can serve as a precise beacon of the relative alignment deviation between composite nanostructures.