Topologically protected vortex transport via chiral-symmetric disclination

TL;DR

This paper demonstrates a topologically protected method to confine and guide high-order vortices using disclinations in photonic lattices, combining momentum-space and real-space topological protections for robust vortex transport.

Contribution

It introduces a novel scheme utilizing topological disclinations and chiral symmetry to achieve vortex guidance with topological protection, applicable across various physical systems.

Findings

Successfully guided optical vortices with preserved orbital angular momentum.

Established a universal relation between vortex charge and disclination symmetry.

Demonstrated robustness of vortex transport in a C3-symmetric photonic lattice.

Abstract

Vortex phenomena are ubiquitous in nature, from vortices of quantum particles and living cells [1-7], to whirlpools, tornados, and spiral galaxies. Yet, effective control of vortex transport from one place to another at any scale has thus far remained a challenging goal. Here, by use of topological disclination [8,9], we demonstrate a scheme to confine and guide vortices of arbitrary high-order charges10,11. Such guidance demands a double topological protection: a nontrivial winding in momentum space due to chiral symmetry [12,13] and a nontrivial winding in real space arising from collective complex coupling between vortex modes. We unveil a vorticity-coordinated rotational symmetry, which sets up a universal relation between the topological charge of a guided vortex and the order of rotational symmetry of the disclination structure. As an example, we construct a C3-symmetry photonic lattice with a single-core disclination, thereby achieving robust transport of an optical vortex with preserved orbital angular momentum (OAM) that corresponds solely to one excited vortex mode pinned at zero energy. Our work reveals a fundamental interplay of vorticity, disclination and higher-order topological phases14-16, applicable broadly to different fields, promising in particular for OAM-based photonic applications that require vortex guides, fibers [17,18] and lasers [19].