Plasmonic Twistronics: Discovery of Plasmonic Skyrmion Bags

TL;DR

This paper demonstrates how twisting plasmonic skyrmion lattices creates a moiré superlattice with complex topological features, enabling control over electromagnetic fields for advanced light-matter interactions.

Contribution

It introduces the concept of plasmonic twistronics by creating and analyzing moiré skyrmion superlattices with controllable topological properties using twist angles.

Findings

Moiré skyrmion superlattices exhibit large topological invariants.

The size of skyrmion bags can be tuned by the twist angle.

Complex electric field distributions are measured and characterized.

Abstract

The study of van der Waals heterostructures with an interlayer twist, known as "twistronics", has been instrumental in advancing contemporary condensed matter research. Most importantly, it has underpinned the emergence of a multitude of strongly-correlated phases, many of which derive from the topology of the physical system. Here, we explore the application of the twistronics paradigm in plasmonic systems with nontrivial topology, by creating a moir\'e skyrmion superlattice using two superimposed plasmonic skyrmion lattices, twisted at a "magic" angle. The complex electric field distribution of the moir\'e skyrmion superlattice is measured using time-resolved vector microscopy, revealing that each super-cell possesses very large topological invariants and harbors a "skyrmion bag", the size of which is controllable by the twist angle and center of rotation. Our work shows how twistronics leads to a diversity of topological features in optical fields, providing a new route to locally manipulate electromagnetic field distributions, which is crucial for future structured light-matter interaction.