Structural transition of skyrmion quasiparticles under compression

TL;DR

This paper investigates how external compression induces structural transitions and dynamic behaviors in skyrmion quasiparticles confined in a space, revealing wave propagation, surface motion, and collapse phenomena.

Contribution

It demonstrates the compression-induced lattice transition, wave front propagation, and surface skyrmion motion in skyrmion solids, advancing understanding of topological quasiparticle physics.

Findings

Compression induces skyrmion lattice transitions.

Wave front propagates with abrupt density change.

Surface skyrmions move rapidly and stably under compression.

Abstract

The competition between external drives and interparticle interactions are important for the static and dynamic properties of topological quasiparticles in confined geometries. Here, we study the dynamics of particlelike skyrmions under a current-induced compression, where skyrmions are stabilized in a confined space and form a skyrmion solid. We find that a lattice structural transition of nanoscale skyrmions could be induced by the compression, which depends on the initial lattice configuration and the compression level. The compression effect in the skyrmion solid with strong skyrmion-skyrmion repulsion could produce a wave front showing an abrupt change of the skyrmion density, which may propagate through the skyrmion solid depending on the compression level. Besides, a chain of skyrmions on the surface of the compressed skyrmion solid could show a fast and stable motion along the surface as long as it remains within the driving region. Some skyrmions may collapse during the compression due to the destructive skyrmion-skyrmion collision, which mainly happens in the area around the skyrmion injection boundary between the driving and compressive regions. Our results are useful for understanding the compression physics of quasiparticles carrying nontrivial topology.