Topological magnetoplasmon

TL;DR

This paper reveals that 2D magnetoplasmons exhibit topological properties similar to topological superconductors, predicting new one-way edge modes and zero-frequency states, enriching the understanding of topological phases in classical systems.

Contribution

It demonstrates the topological analogy between 2D magnetoplasmons and topological superconductors, predicting novel edge states and zero modes in classical wave systems.

Findings

Magnetoplasmons have topologically protected edge states.

Prediction of one-way edge magnetoplasmons at magnetic domain interfaces.

Existence of zero-frequency modes at disk boundaries.

Abstract

Classical wave fields are real-valued, ensuring the wave states at opposite frequencies and momenta to be inherently identical. Such a particle-hole symmetry can open up new possibilities for topological phenomena in classical systems. Here we show that the historically studied two-dimensional (2D) magnetoplasmon, which bears gapped bulk states and gapless one-way edge states near zero frequency, is topologically analogous to the 2D topological $p+\Ii p$ superconductor with chiral Majorana edge states and zero modes. We further predict a new type of one-way edge magnetoplasmon at the interface of opposite magnetic domains, and demonstrate the existence of zero-frequency modes bounded at the peripheries of a hollow disk. These findings can be readily verified in experiment, and can greatly enrich the topological phases in bosonic and classical systems.