Topological solitonic macromolecules

Abstract

Being ubiquitous, solitons have particle-like properties, exhibiting behaviour often associated with atoms. Bound solitons emulate dynamics of molecules, though solitonic analogues of polymeric materials have not been considered yet. Here we experimentally create and model soliton polymers, which we call “polyskyrmionomers”, built of atom-like individual solitons characterized by the topological invariant representing the skyrmion number. With the help of nonlinear optical imaging and numerical modelling based on minimizing the free energy, we reveal how topological point defects bind the solitonic quasi-atoms into polyskyrmionomers, featuring linear, branched, and other macromolecule-resembling architectures, as well as allowing for encoding data by spatial distributions of the skyrmion number. Application of oscillating electric fields activates diverse modes of locomotion and internal vibrations of these self-assembled soliton structures, which depend on symmetry of the solitonic macromolecules. Our findings suggest new designs of soliton meta matter, with a potential for the use in fundamental research and technology.

Topological transformation of magnetic hopfion in confined geometries

“…Meanwhile, the midplane magnetization profile changes from the skyrmionium to a skyrmion. Figure 1B shows the preimages of a toron with zero s z at H z = 0.2 T. As shown in the inset of Figure 1B, the toron consists of skyrmion layers aligning across much of the xy plane with a monopole-antimonopole pair located at its upper and lower ends [41] . In addition, the xz midplane crosssectional spin texture of the hopfion [Figure 1C] is a skyrmion-antiskyrmion pair.…”