Research: Topological dipoles of quantum skyrmions

Magnetic skyrmions are tiny, swirling patterns of magnetic moments that behave like particles in magnetic materials. Unlike ordinary particles, however, skyrmions carry an integer topological charge — a kind of built-in “twist” that makes them robust and hard to destroy. Consequently, they have been already proposed as elementary bits for information processing and future memory devices. How can skyrmions be exploited to store, manipulate and transport information? A recent theoretical study published in Physical Review X addresses this question from a fundamental physics perspective, revealing strict constraints on the mobility of basic skyrmion bits. 

In particular, the authors demonstrate that the quantum dynamics of skyrmions is governed by the conservation of a dipole moment linked to their topological charge. Due to this conserved dipole, an isolated skyrmion cannot move freely like a normal particle; its position becomes essentially fixed unless external forces act on it. This remarkable behavior has deep links to the concept of fractons — exotic quasiparticles whose motion is so restricted they challenge our usual understanding of mobility in matter.

Perhaps most intriguingly, the authors show that the mathematics describing skyrmion motion mirrors the physics of electrons confined to the lowest Landau level in extremely strong magnetic fields. This points to the possible existence of novel quantum liquids of skyrmions that could host fractionalized excitations, similar to those found in fractional quantum Hall states. Together, these findings reveal deep theoretical connections between topology, information, and quantum many-body physics, and they motivate future experiments to realize exotic quantum liquids of skyrmions and to test fractonic phenomena in the laboratory. 

Reference: S. Sorn, J. Schmalian, and M. Garst, Phys. Rev. X 15, 041037 (2025)