Topological spin defects of light

TL;DR

This paper introduces a novel class of topological defects in electromagnetic waves called topological spin defects, characterized by zero spin density points with surrounding nontrivial spin textures, potentially enabling advanced imaging and nanoparticle control.

Contribution

It is the first to identify and characterize topological spin defects in light, expanding the understanding of topological phenomena in electromagnetic systems.

Findings

Existence of topological spin defects with quantized topological charge

Examples of isolated and lattice arrangements of these defects

Potential applications in 3D imaging and nanoparticle manipulation

Abstract

Topological defects are found in a variety of systems, and their existence are robust under perturbations due to their topological nature. Here we introduce a new type of topological defects found in electromagnetic waves: topological spin defects. Such a defect is associated with a point where the electromagnetic spin density is zero, and generically have a nontrivial topological spin texture surrounding the defect point. Due to such spin texture, a topological spin defect possesses a quantized topological charge. We provide examples where isolated defect point, periodic or quasi-periodic defect lattices can be created. Such topological spin defect points may find applications in 3D imaging and nanoparticle manipulation.