image: Vector, scalar, and hybrid electromagnetic toroidal vortices.
Credit: by Ren Wang, Yijie Shen.
Toroidal vortices are fascinating three-dimensional (3D) structures. These ring-like structures can form in free air or other fluids, resembling the surface of a donut, which is mathematically known as a torus. In 2022, Nature Photonics published two independent studies that, for the first time, experimentally generated vector and scalar electromagnetic toroidal vortices [Nat. Photon. 16, 523–528 (2022); Nat. Photon. 16, 519–522 (2022); Nat. Photon. 16, 476–477 (2022)].
Recently, a major breakthrough in the field of optical toroidal vortices has been achieved and published in Science Advances [11(8): eads4797, 2025, https://www.science.org/doi/10.1126/sciadv.ads4797]. A team led by Professor Ren Wang from the University of Electronic Science and Technology of China (UESTC) and Professor Yijie Shen from Nanyang Technological University (NTU) has proposed and successfully generated hybrid electromagnetic toroidal vortices (HETVs). The HETVs combines vectorial electromagnetic toroidal vortices and scalar electromagnetic toroidal vortices. This structure integrates key features such as topological skyrmions, transverse orbital angular momentum, spatiotemporal fields, and electromagnetic vortex streets, forming a propagation-stable electromagnetic quasi-particle. This discovery not only brings new perspectives to electromagnetics but also ushers in transformative advancements in future communication and detection technologies.
These scientists summarize the operational principle of their HETVs:
“The principle involves using a coaxial horn antenna to emit a radially polarized pulse and then converts this pulse into a HETV by a designed metasurface. The scalar toroidal vortex carries transverse orbital angular momentum, while the vector toroidal vortex establishes a skyrmion topological texture that enhances interference resistance. Within the HETVs, the vectorial and scalar toroidal vortices are coupled and nested, forming a topological structure that manifests as skyrmion textures in the transverse plane. Besides, a stunning experimental finding was the emergence of “electromagnetic vortex streets” . Subwavelength vortices align like a topological bead chain. The interaction between the vectorial and scalar toroidal vortices gives rise to electromagnetic vortex streets and other novel features.”
“The unique characteristics of HETVs open up opportunities in the field of electromagnetics, particularly for applications in structured wavefront engineering and topologically nontrivial light-matter interactions. HETVs with electromagnetic vortex street features have the potential to stimulate high-order toroidal multipoles in matter or generate intricate interactions with toroidal metamaterials. Besides, the unique topological structure and the transverse OAM could serve as an “invisible hand” for quantum control and novel wave-matter interactions.” The scientists forecast.
“As we reflect on the implications of our findings, I'm particularly excited about how this research could lead to groundbreaking advancements in pushing detection limits and communication systems. The phase and vector vortices in the longitudinal plane, along with the skyrmion texture with subwavelength features in the transverse plane, make HETVs highly promising for achieving high-precision sensing and imaging. And the topology-protected nature of spatiotemporal vortices and skyrmions makes them resistant to certain types of disturbances. Consequently, HETVs, which incorporate these topology-protected features, may present advantages when propagating through perturbations, suggesting that HETVs could further enhance topologically protected data transmission, ensuring stable signal delivery under adverse conditions” The scientists added.
A Single Thunderclap Signals Spring’s Awakening. The discovery of hybrid toroidal vortices may well be the prelude to a technological revolution. When the day comes that 6G signals penetrate the layers of mist or microscopes resolve virus capsid folds, people may look back at this moment and say:
“This twin-ring dance of electromagnetic fields had already paved the way for dimensional breakthroughs in human technology.”
Journal
Science Advances
Article Title
Hybrid Electromagnetic Toroidal Vortices